Merge remote-tracking branch 'origin/patch_force_ipv4'

[elpher.git] / elpher.el

diff --git a/elpher.el b/elpher.el
index 13ec53c..6e885e4 100644 (file)
--- a/elpher.el
+++ b/elpher.el
@@ -1,10 +1,10 @@
-;;; elpher.el --- A friendly gopher client  -*- lexical-binding:t -*-
+;;; elpher.el --- A friendly gopher and gemini client  -*- lexical-binding:t -*-

 
 ;; Copyright (C) 2019 Tim Vaughan
 
 
 ;; Copyright (C) 2019 Tim Vaughan
 

-;; Author: Tim Vaughan <timv@ughan.xyz>
+;; Author: Tim Vaughan <plugd@thelambdalab.xyz>

 ;; Created: 11 April 2019
 ;; Created: 11 April 2019

-;; Version: 2.6.0
+;; Version: 2.7.9

 ;; Keywords: comm gopher
 ;; Homepage: http://thelambdalab.xyz/elpher
 ;; Package-Requires: ((emacs "26"))
 ;; Keywords: comm gopher
 ;; Homepage: http://thelambdalab.xyz/elpher
 ;; Package-Requires: ((emacs "26"))


@@ -26,8 +26,8 @@
 
 ;;; Commentary:
 
 
 ;;; Commentary:
 

-;; Elpher aims to provide a practical and friendly gopher client
-;; for GNU Emacs.  It supports:
+;; Elpher aims to provide a practical and friendly gopher and gemini
+;; client for GNU Emacs.  It supports:

 
 ;; - intuitive keyboard and mouse-driven browsing,
 ;; - out-of-the-box compatibility with evil-mode,
 
 ;; - intuitive keyboard and mouse-driven browsing,
 ;; - out-of-the-box compatibility with evil-mode,


@@ -36,7 +36,7 @@
 ;; - pleasant and configurable colouring of Gopher directories,
 ;; - direct visualisation of image files,
 ;; - a simple bookmark management system,
 ;; - pleasant and configurable colouring of Gopher directories,
 ;; - direct visualisation of image files,
 ;; - a simple bookmark management system,

-;; - connections using TLS encryption,
+;; - gopher connections using TLS encryption,

 ;; - the fledgling Gemini protocol,
 ;; - the greybeard Finger protocol.
 
 ;; - the fledgling Gemini protocol,
 ;; - the greybeard Finger protocol.
 


@@ -64,12 +64,13 @@
 (require 'subr-x)
 (require 'dns)
 (require 'ansi-color)
 (require 'subr-x)
 (require 'dns)
 (require 'ansi-color)

+(require 'nsm)

 
 
 ;;; Global constants
 ;;
 
 
 
 ;;; Global constants
 ;;
 

-(defconst elpher-version "2.6.0"
+(defconst elpher-version "2.7.9"

   "Current version of elpher.")
 
 (defconst elpher-margin-width 6
   "Current version of elpher.")
 
 (defconst elpher-margin-width 6


@@ -105,8 +106,72 @@
   "A gopher client."
   :group 'applications)
 
   "A gopher client."
   :group 'applications)
 

+;; General appearance and customizations
+
+(defcustom elpher-open-urls-with-eww nil
+  "If non-nil, open URL selectors using eww.
+Otherwise, use the system browser via the BROWSE-URL function."
+  :type '(boolean))
+
+(defcustom elpher-use-header t
+  "If non-nil, display current page information in buffer header."
+  :type '(boolean))
+
+(defcustom elpher-auto-disengage-TLS nil
+  "If non-nil, automatically disengage TLS following an unsuccessful connection.
+While enabling this may seem convenient, it is also potentially dangerous as it
+allows switching from an encrypted channel back to plain text without user input."
+  :type '(boolean))
+
+(defcustom elpher-connection-timeout 5
+  "Specifies the number of seconds to wait for a network connection to time out."
+  :type '(integer))
+
+(defcustom elpher-filter-ansi-from-text nil
+  "If non-nil, filter ANSI escape sequences from text.
+The default behaviour is to use the ansi-color package to interpret these
+sequences."
+  :type '(boolean))
+
+(defcustom elpher-gemini-TLS-cert-checks nil
+  "If non-nil, verify gemini server TLS certs using the default security level.
+Otherwise, certificate verification is disabled.
+
+This defaults to off because it is standard practice for Gemini servers
+to use self-signed certificates, meaning that most servers provide what
+EMACS considers to be an invalid certificate."
+  :type '(boolean))
+
+(defcustom elpher-gemini-max-fill-width 80
+  "Specify the maximum default width (in columns) of text/gemini documents.
+The actual width used is the minimum of this value and the window width at
+the time when the text is rendered."
+  :type '(integer))
+
+(defcustom elpher-gemini-link-string "→ "
+  "Specify the string used to indicate links when rendering gemini maps.
+May be empty."
+  :type '(string))
+
+(defcustom elpher-gemini-bullet-string "•"
+  "Specify the string used for bullets when rendering gemini maps."
+  :type '(string))
+
+(defcustom elpher-bookmarks-file (locate-user-emacs-file "elpher-bookmarks")
+  "Specify the name of the file where elpher bookmarks will be saved."
+  :type '(file))
+
+(defcustom elpher-force-ipv4 nil
+  "If non-nil, force elpher to use ipv4 instead of trying an ipv6 address
+and falling back to an ipv4 address"
+  :type '(boolean))
+

 ;; Face customizations
 
 ;; Face customizations
 

+(defgroup elpher-faces nil
+  "Elpher face customizations."
+  :group 'elpher)
+

 (defface elpher-index
   '((t :inherit font-lock-keyword-face))
   "Face used for directory type directory records.")
 (defface elpher-index
   '((t :inherit font-lock-keyword-face))
   "Face used for directory type directory records.")


@@ -133,7 +198,7 @@
 
 (defface elpher-gemini
   '((t :inherit font-lock-regexp-grouping-backslash))
 
 (defface elpher-gemini
   '((t :inherit font-lock-regexp-grouping-backslash))

-  "Face used for html type directory records.")
+  "Face used for Gemini type directory records.")

 
 (defface elpher-other-url
   '((t :inherit font-lock-comment-face))
 
 (defface elpher-other-url
   '((t :inherit font-lock-comment-face))


@@ -159,32 +224,21 @@
   '((t :inherit shadow))
   "Face used for brackets around directory margin key.")
 
   '((t :inherit shadow))
   "Face used for brackets around directory margin key.")
 

-;; Other customizations
-
-(defcustom elpher-open-urls-with-eww nil
-  "If non-nil, open URL selectors using eww.
-Otherwise, use the system browser via the BROWSE-URL function."
-  :type '(boolean))
-
-(defcustom elpher-use-header t
-  "If non-nil, display current page information in buffer header."
-  :type '(boolean))
+(defface elpher-gemini-heading1
+  '((t :inherit bold :height 1.8))
+  "Face used for gemini heading level 1.")

 
 

-(defcustom elpher-auto-disengage-TLS nil
-  "If non-nil, automatically disengage TLS following an unsuccessful connection.
-While enabling this may seem convenient, it is also potentially dangerous as it
-allows switching from an encrypted channel back to plain text without user input."
-  :type '(boolean))
+(defface elpher-gemini-heading2
+  '((t :inherit bold :height 1.5))
+  "Face used for gemini heading level 2.")

 
 

-(defcustom elpher-connection-timeout 5
-  "Specifies the number of seconds to wait for a network connection to time out."
-  :type '(integer))
+(defface elpher-gemini-heading3
+  '((t :inherit bold :height 1.2))
+  "Face used for gemini heading level 3.")

 
 

-(defcustom elpher-filter-ansi-from-text nil
-  "If non-nil, filter ANSI escape sequences from text.
-The default behaviour is to use the ansi-color package to interpret these
-sequences."
-  :type '(boolean))
+(defface elpher-gemini-preformatted
+  '((t :inherit fixed-pitch))
+  "Face used for pre-formatted gemini text blocks.")

 
 ;;; Model
 ;;
 
 ;;; Model
 ;;


@@ -229,6 +283,7 @@ The basic attributes include: TYPE, SELECTOR, HOST and PORT.
 If the optional attribute TLS is non-nil, the address will be marked as
 requiring gopher-over-TLS."
   (cond
 If the optional attribute TLS is non-nil, the address will be marked as
 requiring gopher-over-TLS."
   (cond

+   ((equal type ?i) nil)

    ((and (equal type ?h)
          (string-prefix-p "URL:" selector))
     (elpher-address-from-url (elt (split-string selector "URL:") 1)))
    ((and (equal type ?h)
          (string-prefix-p "URL:" selector))
     (elpher-address-from-url (elt (split-string selector "URL:") 1)))


@@ -317,7 +372,7 @@ If no address is defined, returns 0.  (This is for compatibility with the URL li
   "Retrieve gopher selector from ADDRESS object."
   (if (member (url-filename address) '("" "/"))
       ""
   "Retrieve gopher selector from ADDRESS object."
   (if (member (url-filename address) '("" "/"))
       ""

-    (substring (url-filename address) 2)))
+    (url-unhex-string (substring (url-filename address) 2))))

 
 
 ;; Cache
 
 
 ;; Cache


@@ -356,6 +411,10 @@ If no address is defined, returns 0.  (This is for compatibility with the URL li
   "Retrieve the address corresponding to PAGE."
   (elt page 1))
 
   "Retrieve the address corresponding to PAGE."
   (elt page 1))
 

+(defun elpher-page-set-address (page new-address)
+  "Set the address corresponding to PAGE to NEW-ADDRESS."
+  (setcar (cdr page) new-address))
+

 (defvar elpher-current-page nil)
 (defvar elpher-history nil)
 
 (defvar elpher-current-page nil)
 (defvar elpher-history nil)
 


@@ -392,7 +451,7 @@ unless NO-HISTORY is non-nil."
   (let ((previous-page (pop elpher-history)))
     (if previous-page
         (elpher-visit-page previous-page nil t)
   (let ((previous-page (pop elpher-history)))
     (if previous-page
         (elpher-visit-page previous-page nil t)

-      (error "No previous page."))))
+      (error "No previous page"))))

       
 (defun elpher-reload-current-page ()
   "Reload the current page, discarding any existing cached content."
       
 (defun elpher-reload-current-page ()
   "Reload the current page, discarding any existing cached content."


@@ -434,6 +493,8 @@ unless NO-HISTORY is non-nil."
   (list 'with-current-buffer "*elpher*"
         '(elpher-mode)
         (append (list 'let '((inhibit-read-only t))
   (list 'with-current-buffer "*elpher*"
         '(elpher-mode)
         (append (list 'let '((inhibit-read-only t))

+                      '(setq-local network-security-level
+                                   (default-value 'network-security-level))

                       '(erase-buffer)
                       '(elpher-update-header))
                 args)))
                       '(erase-buffer)
                       '(elpher-update-header))
                 args)))


@@ -504,9 +565,12 @@ to ADDRESS."
     (error "Cannot retrieve gopher selector: port number > 65536"))
   (condition-case nil
       (let* ((kill-buffer-query-functions nil)
     (error "Cannot retrieve gopher selector: port number > 65536"))
   (condition-case nil
       (let* ((kill-buffer-query-functions nil)

+             (gnutls-verify-error nil) ; We use the NSM for verification

              (port (elpher-address-port address))
              (host (elpher-address-host address))
              (port (elpher-address-port address))
              (host (elpher-address-host address))

-             (selector-string "")
+             (selector-string-parts nil)
+             (bytes-received 0)
+             (hkbytes-received 0)

              (proc (open-network-stream "elpher-process"
                                         nil
                                         (if force-ipv4 (dns-query host) host)
              (proc (open-network-stream "elpher-process"
                                         nil
                                         (if force-ipv4 (dns-query host) host)


@@ -526,7 +590,7 @@ to ADDRESS."
                                           (progn
                                             (message "Disabling TLS mode.")
                                             (setq elpher-use-tls nil)
                                           (progn
                                             (message "Disabling TLS mode.")
                                             (setq elpher-use-tls nil)

-                                            (elpher-get-selector address renderer))
+                                            (elpher-get-selector address renderer elpher-force-ipv4))

                                         (elpher-network-error address "Could not establish encrypted connection")))
                                      ('connect
                                       (elpher-process-cleanup)
                                         (elpher-network-error address "Could not establish encrypted connection")))
                                      ('connect
                                       (elpher-process-cleanup)


@@ -537,9 +601,23 @@ to ADDRESS."
         (set-process-coding-system proc 'binary)
         (set-process-filter proc
                             (lambda (_proc string)
         (set-process-coding-system proc 'binary)
         (set-process-filter proc
                             (lambda (_proc string)

-                              (cancel-timer timer)
-                              (setq selector-string
-                                    (concat selector-string string))))
+                              (when timer
+                                (cancel-timer timer)
+                                (setq timer nil))
+                              (setq bytes-received (+ bytes-received (length string)))
+                              (let ((new-hkbytes-received (/ bytes-received 102400)))
+                                (when (> new-hkbytes-received hkbytes-received)
+                                  (setq hkbytes-received new-hkbytes-received)
+                                  (with-current-buffer "*elpher*"
+                                    (let ((inhibit-read-only t))
+                                      (goto-char (point-min))
+                                      (beginning-of-line 2)
+                                      (delete-region (point) (point-max))
+                                      (insert "("
+                                              (number-to-string (/ hkbytes-received 10.0))
+                                              " MB read)")))))
+                              (setq selector-string-parts
+                                    (cons string selector-string-parts))))

         (set-process-sentinel proc
                               (lambda (_proc event)
                                 (condition-case the-error
         (set-process-sentinel proc
                               (lambda (_proc event)
                                 (condition-case the-error


@@ -552,8 +630,11 @@ to ADDRESS."
                                          (concat (elpher-gopher-address-selector address)
                                                  "\r\n"))))
                                      (t
                                          (concat (elpher-gopher-address-selector address)
                                                  "\r\n"))))
                                      (t

-                                      (cancel-timer timer)
-                                      (funcall renderer selector-string)
+                                      (when timer
+                                        (cancel-timer timer)
+                                        (setq timer nil))
+                                      (funcall renderer (apply #'concat
+                                                               (reverse selector-string-parts)))

                                       (elpher-restore-pos)))
                                   (error
                                    (elpher-network-error address the-error))))))
                                       (elpher-restore-pos)))
                                   (error
                                    (elpher-network-error address the-error))))))


@@ -571,9 +652,9 @@ once they are retrieved from the gopher server."
          (insert content)
          (elpher-restore-pos))
       (elpher-with-clean-buffer
          (insert content)
          (elpher-restore-pos))
       (elpher-with-clean-buffer

-       (insert "LOADING... (use 'u' to cancel)"))
+       (insert "LOADING... (use 'u' to cancel)\n"))

       (condition-case the-error
       (condition-case the-error

-          (elpher-get-selector address renderer)
+          (elpher-get-selector address renderer elpher-force-ipv4)

         (error
          (elpher-network-error address the-error))))))
 
         (error
          (elpher-network-error address the-error))))))
 


@@ -610,12 +691,19 @@ once they are retrieved from the gopher server."
         (insert " "))
     (insert (make-string elpher-margin-width ?\s))))
 
         (insert " "))
     (insert (make-string elpher-margin-width ?\s))))
 

-(defun elpher-page-button-help (page)
-  "Return a string containing the help text for a button corresponding to PAGE."
-  (let ((address (elpher-page-address page)))
-    (format "mouse-1, RET: open '%s'" (if (elpher-address-special-p address)
-                                          address
-                                        (elpher-address-to-url address)))))
+(defun elpher--page-button-help (_window buffer pos)
+  "Function called by Emacs to generate mouse-over text.
+The arguments specify the BUFFER and the POS within the buffer of the item
+for which help is required.  The function returns the help to be
+displayed.  The _WINDOW argument is currently unused."
+  (with-current-buffer buffer
+    (let ((button (button-at pos)))
+      (when button
+        (let* ((page (button-get button 'elpher-page))
+               (address (elpher-page-address page)))
+          (format "mouse-1, RET: open '%s'" (if (elpher-address-special-p address)
+                                                address
+                                              (url-recreate-url address))))))))

 
 (defun elpher-insert-index-record (display-string &optional address)
   "Function to insert an index record into the current buffer.
 
 (defun elpher-insert-index-record (display-string &optional address)
   "Function to insert an index record into the current buffer.


@@ -635,9 +723,9 @@ If ADDRESS is not supplied or nil the record is rendered as an
                               'elpher-page page
                               'action #'elpher-click-link
                               'follow-link t
                               'elpher-page page
                               'action #'elpher-click-link
                               'follow-link t

-                              'help-echo (elpher-page-button-help page)))
+                              'help-echo #'elpher--page-button-help))

       (pcase type
       (pcase type

-        ((or '(gopher ?i) 'nil) ;; Information
+        ('nil ;; Information

          (elpher-insert-margin)
          (let ((propertized-display-string
                 (propertize display-string 'face 'elpher-info)))
          (elpher-insert-margin)
          (let ((propertized-display-string
                 (propertize display-string 'face 'elpher-info)))


@@ -681,7 +769,7 @@ If ADDRESS is not supplied or nil the record is rendered as an
                             'elpher-page  page
                             'action #'elpher-click-link
                             'follow-link t
                             'elpher-page  page
                             'action #'elpher-click-link
                             'follow-link t

-                            'help-echo (elpher-page-button-help page)
+                            'help-echo #'elpher--page-button-help

                             'face 'button)))
     (buffer-string)))
 
                             'face 'button)))
     (buffer-string)))
 


@@ -746,7 +834,7 @@ The response is rendered using the rendering function RENDERER."
 
             (elpher-with-clean-buffer
              (insert "LOADING RESULTS... (use 'u' to cancel)"))
 
             (elpher-with-clean-buffer
              (insert "LOADING RESULTS... (use 'u' to cancel)"))

-            (elpher-get-selector search-address renderer))
+            (elpher-get-selector search-address renderer elpher-force-ipv4))

         (if aborted
             (elpher-visit-previous-page))))))
  
         (if aborted
             (elpher-visit-previous-page))))))
  


@@ -770,7 +858,9 @@ The response is rendered using the rendering function RENDERER."
   (if (not data)
       nil
     (let* ((address (elpher-page-address elpher-current-page))
   (if (not data)
       nil
     (let* ((address (elpher-page-address elpher-current-page))

-           (selector (elpher-gopher-address-selector address)))
+           (selector (if (elpher-address-gopher-p address)
+                         (elpher-gopher-address-selector address)
+                       (elpher-address-filename address))))

       (elpher-visit-previous-page) ; Do first in case of non-local exits.
       (let* ((filename-proposal (file-name-nondirectory selector))
              (filename (read-file-name "Download complete. Save file as: "
       (elpher-visit-previous-page) ; Do first in case of non-local exits.
       (let* ((filename-proposal (file-name-nondirectory selector))
              (filename (read-file-name "Download complete. Save file as: "


@@ -803,15 +893,21 @@ The response is rendered using the rendering function RENDERER."
   "Retrieve gemini ADDRESS, then render using RENDERER.
 If FORCE-IPV4 is non-nil, explicitly look up and use IPv4 address corresponding
 to ADDRESS."
   "Retrieve gemini ADDRESS, then render using RENDERER.
 If FORCE-IPV4 is non-nil, explicitly look up and use IPv4 address corresponding
 to ADDRESS."

+  (unless elpher-gemini-TLS-cert-checks
+    (setq-local network-security-level 'low))

   (if (not (gnutls-available-p))
       (error "Cannot establish gemini connection: GnuTLS not available")
     (unless (< (elpher-address-port address) 65536)
       (error "Cannot establish gemini connection: port number > 65536"))
   (if (not (gnutls-available-p))
       (error "Cannot establish gemini connection: GnuTLS not available")
     (unless (< (elpher-address-port address) 65536)
       (error "Cannot establish gemini connection: port number > 65536"))

+    (defvar gnutls-verify-error)

     (condition-case nil
         (let* ((kill-buffer-query-functions nil)
     (condition-case nil
         (let* ((kill-buffer-query-functions nil)

+               (gnutls-verify-error nil) ; We use the NSM for verification

                (port (elpher-address-port address))
                (host (elpher-address-host address))
                (port (elpher-address-port address))
                (host (elpher-address-host address))

-               (response-string "")
+               (response-string-parts nil)
+               (bytes-received 0)
+               (hkbytes-received 0)

                (proc (open-network-stream "elpher-process"
                                           nil
                                           (if force-ipv4 (dns-query host) host)
                (proc (open-network-stream "elpher-process"
                                           nil
                                           (if force-ipv4 (dns-query host) host)


@@ -832,8 +928,20 @@ to ADDRESS."
                                 (when timer
                                   (cancel-timer timer)
                                   (setq timer nil))
                                 (when timer
                                   (cancel-timer timer)
                                   (setq timer nil))

-                                (setq response-string
-                                      (concat response-string string))))
+                                (setq bytes-received (+ bytes-received (length string)))
+                                (let ((new-hkbytes-received (/ bytes-received 102400)))
+                                  (when (> new-hkbytes-received hkbytes-received)
+                                    (setq hkbytes-received new-hkbytes-received)
+                                    (with-current-buffer "*elpher*"
+                                      (let ((inhibit-read-only t))
+                                        (goto-char (point-min))
+                                        (beginning-of-line 2)
+                                        (delete-region (point) (point-max))
+                                        (insert "("
+                                                (number-to-string (/ hkbytes-received 10.0))
+                                                " MB read)")))))
+                                (setq response-string-parts
+                                      (cons string response-string-parts))))

           (set-process-sentinel proc
                                 (lambda (proc event)
                                   (condition-case the-error
           (set-process-sentinel proc
                                 (lambda (proc event)
                                   (condition-case the-error


@@ -845,7 +953,7 @@ to ADDRESS."
                                            (concat (elpher-address-to-url address)
                                                    "\r\n"))))
                                        ((string-prefix-p "deleted" event)) ; do nothing
                                            (concat (elpher-address-to-url address)
                                                    "\r\n"))))
                                        ((string-prefix-p "deleted" event)) ; do nothing

-                                       ((and (string-empty-p response-string)
+                                       ((and (not response-string-parts)

                                              (not force-ipv4))
                                         ; Try again with IPv4
                                         (message "Connection failed. Retrying with IPv4.")
                                              (not force-ipv4))
                                         ; Try again with IPv4
                                         (message "Connection failed. Retrying with IPv4.")


@@ -853,11 +961,11 @@ to ADDRESS."
                                         (elpher-get-gemini-response address renderer t))
                                        (t
                                         (funcall #'elpher-process-gemini-response
                                         (elpher-get-gemini-response address renderer t))
                                        (t
                                         (funcall #'elpher-process-gemini-response

-                                                 response-string
+                                                 (apply #'concat (reverse response-string-parts))

                                                  renderer)
                                         (elpher-restore-pos)))
                                     (error
                                                  renderer)
                                         (elpher-restore-pos)))
                                     (error

-                                           (elpher-network-error address the-error))))))
+                                     (elpher-network-error address the-error))))))

       (error
        (error "Error initiating connection to server")))))
 
       (error
        (error "Error initiating connection to server")))))
 


@@ -874,7 +982,7 @@ that the response was malformed."
                     (meta (string-trim (substring header 2))))
                 (list code meta body))
             (error "Malformed response: No response status found in header %s" header)))
                     (meta (string-trim (substring header 2))))
                 (list code meta body))
             (error "Malformed response: No response status found in header %s" header)))

-      (error "Malformed response: No CRLF-delimited header found"))))
+      (error "Malformed response: No CRLF-delimited header found in response %s" response))))

 
 (defun elpher-process-gemini-response (response-string renderer)
   "Process the gemini response RESPONSE-STRING and pass the result to RENDERER."
 
 (defun elpher-process-gemini-response (response-string renderer)
   "Process the gemini response RESPONSE-STRING and pass the result to RENDERER."


@@ -903,6 +1011,7 @@ that the response was malformed."
                              "gemini"))
                (error "Server tried to automatically redirect to non-gemini URL: %s"
                       response-meta))
                              "gemini"))
                (error "Server tried to automatically redirect to non-gemini URL: %s"
                       response-meta))

+           (elpher-page-set-address elpher-current-page redirect-address)

            (add-to-list 'elpher-gemini-redirect-chain redirect-address)
            (elpher-get-gemini-response redirect-address renderer)))
         (?4 ; Temporary failure
            (add-to-list 'elpher-gemini-redirect-chain redirect-address)
            (elpher-get-gemini-response redirect-address renderer)))
         (?4 ; Temporary failure


@@ -927,7 +1036,7 @@ that the response was malformed."
               (insert content)
               (elpher-restore-pos))
           (elpher-with-clean-buffer
               (insert content)
               (elpher-restore-pos))
           (elpher-with-clean-buffer

-           (insert "LOADING GEMINI... (use 'u' to cancel)"))
+           (insert "LOADING GEMINI... (use 'u' to cancel)\n"))

           (setq elpher-gemini-redirect-chain nil)
           (elpher-get-gemini-response address renderer))
       (error
           (setq elpher-gemini-redirect-chain nil)
           (elpher-get-gemini-response address renderer))
       (error


@@ -966,19 +1075,25 @@ that the response was malformed."
         ((pred (string-prefix-p "image/"))
          (elpher-render-image body))
         (_other
         ((pred (string-prefix-p "image/"))
          (elpher-render-image body))
         (_other

-         (error "Unsupported MIME type %S" mime-type))))))
-
-(defun elpher-gemini-get-link-url (line)
-  "Extract the url portion of LINE, a gemini map file link line."
-  (string-trim (elt (split-string (substring line 2)) 0)))
-
-(defun elpher-gemini-get-link-display-string (line)
-  "Extract the display string portion of LINE, a gemini map file link line."
-  (let* ((rest (string-trim (elt (split-string line "=>") 1)))
+         (elpher-render-download body))))))
+
+(defun elpher-gemini-get-link-url (link-line)
+  "Extract the url portion of LINK-LINE, a gemini map file link line.
+Returns nil in the event that the contents of the line following the
+=> prefix are empty."
+  (let ((l (split-string (substring link-line 2))))
+    (if l
+        (string-trim (elt l 0))
+      nil)))
+
+(defun elpher-gemini-get-link-display-string (link-line)
+  "Extract the display string portion of LINK-LINE, a gemini map file link line.
+Returns the url portion in the event that the display-string portion is empty."
+  (let* ((rest (string-trim (elt (split-string link-line "=>") 1)))

          (idx (string-match "[ \t]" rest)))
          (idx (string-match "[ \t]" rest)))

-    (if idx
-        (string-trim (substring rest (+ idx 1)))
-      "")))
+    (string-trim (if idx
+                     (substring rest (+ idx 1))
+                   rest))))

 
 (defun elpher-collapse-dot-sequences (filename)
   "Collapse dot sequences in FILENAME.
 
 (defun elpher-collapse-dot-sequences (filename)
   "Collapse dot sequences in FILENAME.


@@ -1014,18 +1129,78 @@ For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
                 (elpher-collapse-dot-sequences (url-filename address)))))
     address))
 
                 (elpher-collapse-dot-sequences (url-filename address)))))
     address))
 

+(defun elpher-gemini-insert-link (link-line)
+  "Insert link described by LINK-LINE into a text/gemini document."
+  (let* ((url (elpher-gemini-get-link-url link-line))
+         (display-string (elpher-gemini-get-link-display-string link-line))
+         (address (elpher-address-from-gemini-url url))
+         (type (if address (elpher-address-type address) nil))
+         (type-map-entry (cdr (assoc type elpher-type-map))))
+    (when display-string
+      (insert elpher-gemini-link-string)
+      (if type-map-entry
+          (let* ((face (elt type-map-entry 3))
+                 (filtered-display-string (ansi-color-filter-apply display-string))
+                 (page (elpher-make-page filtered-display-string address)))
+            (insert-text-button filtered-display-string
+                                'face face
+                                'elpher-page page
+                                'action #'elpher-click-link
+                                'follow-link t
+                                'help-echo #'elpher--page-button-help))
+        (insert (propertize display-string 'face 'elpher-unknown)))
+      (insert "\n"))))
+  
+(defun elpher-gemini-insert-header (header-line)
+  "Insert header described by HEADER-LINE into a text/gemini document.
+The gemini map file line describing the header is given
+by HEADER-LINE."
+  (when (string-match "^\\(#+\\)[ \t]*" header-line)
+    (let ((level (length (match-string 1 header-line)))
+          (header (substring header-line (match-end 0))))
+      (unless (display-graphic-p)
+        (insert (make-string level ?#) " "))
+      (insert (propertize header 'face
+                          (pcase level
+                            (1 'elpher-gemini-heading1)
+                            (2 'elpher-gemini-heading2)
+                            (3 'elpher-gemini-heading3)
+                            (_ 'default)))
+              "\n"))))
+
+(defun elpher-gemini-insert-text (text-line)
+  "Insert a plain non-preformatted TEXT-LINE into a text/gemini document.
+This function uses Emacs' auto-fill to wrap text sensibly to a maximum
+width defined by elpher-gemini-max-fill-width."
+  (string-match "\\(^[ \t]*\\)\\(\*[ \t]\\)?" text-line)
+  (let* ((processed-text-line (if (match-string 2 text-line)
+                                  (concat
+                                   (replace-regexp-in-string "\*"
+                                                             elpher-gemini-bullet-string
+                                                             (match-string 0 text-line))
+                                   (substring text-line (match-end 0)))
+                                text-line))
+         (fill-prefix (if (match-string 1 text-line)
+                          (replace-regexp-in-string "\*" " " (match-string 0 text-line))
+                        nil)))
+    (insert (elpher-process-text-for-display processed-text-line))
+    (newline)))
+

 (defun elpher-render-gemini-map (data _parameters)
   "Render DATA as a gemini map file, PARAMETERS is currently unused."
   (elpher-with-clean-buffer
 (defun elpher-render-gemini-map (data _parameters)
   "Render DATA as a gemini map file, PARAMETERS is currently unused."
   (elpher-with-clean-buffer

-   (dolist (line (split-string data "\n"))
-     (if (string-prefix-p "=>" line)
-         (let* ((url (elpher-gemini-get-link-url line))
-                (display-string (elpher-gemini-get-link-display-string line))
-                (address (elpher-address-from-gemini-url url)))
-           (if (> (length display-string) 0)
-               (elpher-insert-index-record display-string address)
-             (elpher-insert-index-record url address)))
-       (elpher-insert-index-record line)))
+   (let ((preformatted nil))
+     (auto-fill-mode 1)
+     (setq-local fill-column (min (window-width) elpher-gemini-max-fill-width))
+     (dolist (line (split-string data "\n"))
+       (cond
+        ((string-prefix-p "```" line) (setq preformatted (not preformatted)))
+        (preformatted (insert (elpher-process-text-for-display
+                               (propertize line 'face 'elpher-gemini-preformatted))
+                              "\n"))
+        ((string-prefix-p "=>" line) (elpher-gemini-insert-link line))
+        ((string-prefix-p "#" line) (elpher-gemini-insert-header line))
+        (t (elpher-gemini-insert-text line)))))

    (elpher-cache-content
     (elpher-page-address elpher-current-page)
     (buffer-string))))
    (elpher-cache-content
     (elpher-page-address elpher-current-page)
     (buffer-string))))


@@ -1041,7 +1216,10 @@ For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
 ;; Finger page connection
 
 (defun elpher-get-finger-page (renderer &optional force-ipv4)
 ;; Finger page connection
 
 (defun elpher-get-finger-page (renderer &optional force-ipv4)

-  "Opens a finger connection to the current page address and renders it using RENDERER."
+  "Opens a finger connection to the current page address.
+The result is rendered using RENDERER.  When the optional argument
+FORCE-IPV4 is non-nil, the IPv4 address returned by a DNS lookup will
+be used explicitly in making the connection."

   (let* ((address (elpher-page-address elpher-current-page))
          (content (elpher-get-cached-content address)))
     (if (and content (funcall renderer nil))
   (let* ((address (elpher-page-address elpher-current-page))
          (content (elpher-get-cached-content address)))
     (if (and content (funcall renderer nil))


@@ -1049,7 +1227,7 @@ For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
          (insert content)
          (elpher-restore-pos))
       (elpher-with-clean-buffer
          (insert content)
          (elpher-restore-pos))
       (elpher-with-clean-buffer

-       (insert "LOADING... (use 'u' to cancel)"))
+       (insert "LOADING... (use 'u' to cancel)\n"))

       (condition-case the-error
           (let* ((kill-buffer-query-functions nil)
                  (user (let ((filename (elpher-address-filename address)))
       (condition-case the-error
           (let* ((kill-buffer-query-functions nil)
                  (user (let ((filename (elpher-address-filename address)))


@@ -1059,7 +1237,7 @@ For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
                  (port (let ((given-port (elpher-address-port address)))
                          (if (> given-port 0) given-port 79)))
                  (host (elpher-address-host address))
                  (port (let ((given-port (elpher-address-port address)))
                          (if (> given-port 0) given-port 79)))
                  (host (elpher-address-host address))

-                 (selector-string "")
+                 (selector-string-parts nil)

                  (proc (open-network-stream "elpher-process"
                                             nil
                                             (if force-ipv4 (dns-query host) host)
                  (proc (open-network-stream "elpher-process"
                                             nil
                                             (if force-ipv4 (dns-query host) host)


@@ -1079,12 +1257,14 @@ For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
             (set-process-coding-system proc 'binary)
             (set-process-filter proc
                                 (lambda (_proc string)
             (set-process-coding-system proc 'binary)
             (set-process-filter proc
                                 (lambda (_proc string)

-                                  (cancel-timer timer)
-                                  (setq selector-string
-                                        (concat selector-string string))))
+                                  (when timer
+                                    (cancel-timer timer)
+                                    (setq timer nil))
+                                  (setq selector-string-parts
+                                        (cons string selector-string-parts))))

             (set-process-sentinel proc
                                   (lambda (_proc event)
             (set-process-sentinel proc
                                   (lambda (_proc event)

-                                    (condition-case the-error
+                                    (condition-case _the-error

                                         (cond
                                          ((string-prefix-p "deleted" event))
                                          ((string-prefix-p "open" event)
                                         (cond
                                          ((string-prefix-p "deleted" event))
                                          ((string-prefix-p "open" event)


@@ -1093,8 +1273,11 @@ For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
                                              proc
                                              (concat user "\r\n"))))
                                          (t
                                              proc
                                              (concat user "\r\n"))))
                                          (t

-                                          (cancel-timer timer)
-                                          (funcall renderer selector-string)
+                                          (when timer
+                                            (cancel-timer timer)
+                                            (setq timer nil))
+                                          (funcall renderer (apply #'concat
+                                                                   (reverse selector-string-parts)))

                                           (elpher-restore-pos)))))))
         (error
          (elpher-network-error address the-error))))))
                                           (elpher-restore-pos)))))))
         (error
          (elpher-network-error address the-error))))))


@@ -1140,7 +1323,7 @@ For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
     (error "Command not supported for start page"))
   (elpher-with-clean-buffer
    (insert "     --------------------------------------------\n"
     (error "Command not supported for start page"))
   (elpher-with-clean-buffer
    (insert "     --------------------------------------------\n"

-           "                Elpher Gopher Client             \n"
+           "           Elpher Gopher and Gemini Client       \n"

            "                   version " elpher-version "\n"
            "     --------------------------------------------\n"
            "\n"
            "                   version " elpher-version "\n"
            "     --------------------------------------------\n"
            "\n"


@@ -1149,9 +1332,9 @@ For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
            " - TAB/Shift-TAB: next/prev item on current page\n"
            " - RET/mouse-1: open item under cursor\n"
            " - m: select an item on current page by name (autocompletes)\n"
            " - TAB/Shift-TAB: next/prev item on current page\n"
            " - RET/mouse-1: open item under cursor\n"
            " - m: select an item on current page by name (autocompletes)\n"

-           " - u/mouse-3: return to previous page\n"
+           " - u/mouse-3/U: return to previous page or to the start page\n"

            " - o/O: visit different selector or the root menu of the current server\n"
            " - o/O: visit different selector or the root menu of the current server\n"

-           " - g: go to a particular gopher address\n"
+           " - g: go to a particular address (gopher, gemini, finger)\n"

            " - d/D: download item under cursor or current page\n"
            " - i/I: info on item under cursor or current page\n"
            " - c/C: copy URL representation of item under cursor or current page\n"
            " - d/D: download item under cursor or current page\n"
            " - i/I: info on item under cursor or current page\n"
            " - c/C: copy URL representation of item under cursor or current page\n"


@@ -1164,13 +1347,17 @@ For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
            " - T: toggle TLS gopher mode\n"
            " - .: display the raw server response for the current page\n"
            "\n"
            " - T: toggle TLS gopher mode\n"
            " - .: display the raw server response for the current page\n"
            "\n"

-           "Start your exploration of gopher space:\n")
+           "Start your exploration of gopher space and gemini:\n")

    (elpher-insert-index-record "Floodgap Systems Gopher Server"
                                (elpher-make-gopher-address ?1 "" "gopher.floodgap.com" 70))
    (elpher-insert-index-record "Floodgap Systems Gopher Server"
                                (elpher-make-gopher-address ?1 "" "gopher.floodgap.com" 70))

+   (elpher-insert-index-record "Project Gemini home page"
+                               (elpher-address-from-url "gemini://gemini.circumlunar.space/"))

    (insert "\n"
    (insert "\n"

-           "Alternatively, select the following item and enter some search terms:\n")
-   (elpher-insert-index-record "Veronica-2 Gopher Search Engine"
+           "Alternatively, select a search engine and enter some search terms:\n")
+   (elpher-insert-index-record "Gopher Search Engine (Veronica-2)"

                                (elpher-make-gopher-address ?7 "/v2/vs" "gopher.floodgap.com" 70))
                                (elpher-make-gopher-address ?7 "/v2/vs" "gopher.floodgap.com" 70))

+   (elpher-insert-index-record "Gemini Search Engine (GUS)"
+                               (elpher-address-from-url "gemini://gus.guru/search"))

    (insert "\n"
            "This page contains your bookmarked sites (also visit with B):\n")
    (elpher-insert-index-record "Your Bookmarks" 'bookmarks)
    (insert "\n"
            "This page contains your bookmarked sites (also visit with B):\n")
    (elpher-insert-index-record "Your Bookmarks" 'bookmarks)


@@ -1221,7 +1408,7 @@ For instance, the filename /a/b/../c/./d will reduce to /a/c/d"
            "- a: rename selected bookmark\n"
            "\n"
            "Bookmarks are stored in the file ")
            "- a: rename selected bookmark\n"
            "\n"
            "Bookmarks are stored in the file ")

-   (let ((filename (locate-user-emacs-file "elpher-bookmarks"))
+   (let ((filename elpher-bookmarks-file)

          (help-string "RET,mouse-1: Open bookmarks file in new buffer for editing."))
      (insert-text-button filename
                          'face 'link
          (help-string "RET,mouse-1: Open bookmarks file in new buffer for editing."))
      (insert-text-button filename
                          'face 'link


@@ -1258,7 +1445,7 @@ bookmark list, while URL is the url of the entry."
 (defun elpher-save-bookmarks (bookmarks)
   "Record the bookmark list BOOKMARKS to the user's bookmark file.
 Beware that this completely replaces the existing contents of the file."
 (defun elpher-save-bookmarks (bookmarks)
   "Record the bookmark list BOOKMARKS to the user's bookmark file.
 Beware that this completely replaces the existing contents of the file."

-  (with-temp-file (locate-user-emacs-file "elpher-bookmarks")
+  (with-temp-file elpher-bookmarks-file

     (erase-buffer)
     (insert "; Elpher bookmarks file\n\n"
             "; Bookmarks are stored as a list of (label URL) items.\n"
     (erase-buffer)
     (insert "; Elpher bookmarks file\n\n"
             "; Bookmarks are stored as a list of (label URL) items.\n"


@@ -1271,7 +1458,7 @@ Beware that this completely replaces the existing contents of the file."
   (let ((bookmarks
          (with-temp-buffer
            (ignore-errors
   (let ((bookmarks
          (with-temp-buffer
            (ignore-errors

-             (insert-file-contents (locate-user-emacs-file "elpher-bookmarks"))
+             (insert-file-contents elpher-bookmarks-file)

              (goto-char (point-min))
              (read (current-buffer))))))
     (if (and bookmarks (listp (cadar bookmarks)))
              (goto-char (point-min))
              (read (current-buffer))))))
     (if (and bookmarks (listp (cadar bookmarks)))


@@ -1374,6 +1561,15 @@ When run interactively HOST-OR-URL is read from the minibuffer."
   (interactive)
   (elpher-visit-previous-page))
 
   (interactive)
   (elpher-visit-previous-page))
 

+(defun elpher-back-to-start ()
+  "Go all the way back to the start page."
+  (interactive)
+  (setq elpher-current-page nil)
+  (setq elpher-history nil)
+  (let ((start-page (elpher-make-page "Elpher Start Page"
+                                      (elpher-make-special-address 'start))))
+    (elpher-visit-page start-page)))
+

 (defun elpher-download ()
   "Download the link at point."
   (interactive)
 (defun elpher-download ()
   "Download the link at point."
   (interactive)


@@ -1433,9 +1629,7 @@ When run interactively HOST-OR-URL is read from the minibuffer."
           (let ((address-copy (elpher-address-from-url
                                (elpher-address-to-url address))))
             (setf (url-filename address-copy) "")
           (let ((address-copy (elpher-address-from-url
                                (elpher-address-to-url address))))
             (setf (url-filename address-copy) "")

-            (elpher-visit-page
-             (elpher-make-page (elpher-address-to-url address-copy)
-                               address-copy))))
+            (elpher-go (elpher-address-to-url address-copy))))

       (error "Command invalid for %s" (elpher-page-display-string elpher-current-page)))))
 
 (defun elpher-bookmarks-current-p ()
       (error "Command invalid for %s" (elpher-page-display-string elpher-current-page)))))
 
 (defun elpher-bookmarks-current-p ()


@@ -1563,7 +1757,9 @@ When run interactively HOST-OR-URL is read from the minibuffer."
   (let ((map (make-sparse-keymap)))
     (define-key map (kbd "TAB") 'elpher-next-link)
     (define-key map (kbd "<backtab>") 'elpher-prev-link)
   (let ((map (make-sparse-keymap)))
     (define-key map (kbd "TAB") 'elpher-next-link)
     (define-key map (kbd "<backtab>") 'elpher-prev-link)

+    (define-key map (kbd "C-M-i") 'elpher-prev-link)

     (define-key map (kbd "u") 'elpher-back)
     (define-key map (kbd "u") 'elpher-back)

+    (define-key map (kbd "U") 'elpher-back-to-start)

     (define-key map [mouse-3] 'elpher-back)
     (define-key map (kbd "O") 'elpher-root-dir)
     (define-key map (kbd "g") 'elpher-go)
     (define-key map [mouse-3] 'elpher-back)
     (define-key map (kbd "O") 'elpher-root-dir)
     (define-key map (kbd "g") 'elpher-go)


@@ -1591,6 +1787,7 @@ When run interactively HOST-OR-URL is read from the minibuffer."
         (kbd "C-") 'elpher-follow-current-link
         (kbd "C-t") 'elpher-back
         (kbd "u") 'elpher-back
         (kbd "C-") 'elpher-follow-current-link
         (kbd "C-t") 'elpher-back
         (kbd "u") 'elpher-back

+        (kbd "U") 'elpher-back-to-start

         [mouse-3] 'elpher-back
         (kbd "g") 'elpher-go
         (kbd "o") 'elpher-go-current
         [mouse-3] 'elpher-back
         (kbd "g") 'elpher-go
         (kbd "o") 'elpher-go-current


@@ -1636,6 +1833,7 @@ functions which initialize the gopher client, namely
       (switch-to-buffer "*elpher*")
     (switch-to-buffer "*elpher*")
     (setq elpher-current-page nil)
       (switch-to-buffer "*elpher*")
     (switch-to-buffer "*elpher*")
     (setq elpher-current-page nil)

+    (setq elpher-history nil)

     (let ((start-page (elpher-make-page "Elpher Start Page"
                                         (elpher-make-special-address 'start))))
       (elpher-visit-page start-page)))
     (let ((start-page (elpher-make-page "Elpher Start Page"
                                         (elpher-make-special-address 'start))))
       (elpher-visit-page start-page)))