[elpa] externals/auctex 59ccf34 35/36: Check the viewer executable exists before opening it.

[Stefan Monnier]

branch: externals/auctex
commit 59ccf3416d53064785d3feee8bcbf8074612386a
Author: Mosè Giordano <address@hidden>
Date:   Fri Nov 28 15:58:06 2014 +0100

    Check the viewer executable exists before opening it.
    
    * tex.el (TeX-view-program-list-builtin): Add the new third
    element to each item.
    (TeX-view-program-list): Document new third element of items in
    doc string.  Adapt the type.
    (TeX-view-command-raw): Check whether the viewer executable
    exists.  (Bug#19121)
    
    * doc/auctex.texi (Starting Viewers): Document change to
    `TeX-view-program-list'.
    
    * doc/changes.texi: Mention it.
---
 ChangeLog        |   14 ++++++
 doc/auctex.texi  |    6 +++
 doc/changes.texi |    4 ++
 tex.el           |  123 ++++++++++++++++++++++++++++++++---------------------
 4 files changed, 98 insertions(+), 49 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 95ee0ea..6c0c802 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2014-11-28  Mos� Giordano  <address@hidden>
+
+       * tex.el (TeX-view-program-list-builtin): Add the new third
+       element to each item.
+       (TeX-view-program-list): Document new third element of items in
+       doc string.  Adapt the type.
+       (TeX-view-command-raw): Check whether the viewer executable
+       exists.  (Bug#19121)
+
+       * doc/auctex.texi (Starting Viewers): Document change to
+       `TeX-view-program-list'.
+
+       * doc/changes.texi: Mention it.
+
 2014-11-28  Stefan Monnier  <address@hidden>
 
        * style/siunitx.el (tex): Require tex because its indispensable
diff --git a/doc/auctex.texi b/doc/auctex.texi
index ea22c71..8fb997c 100644
--- a/doc/auctex.texi
+++ b/doc/auctex.texi
@@ -3045,6 +3045,12 @@ exact format to use.)  The command line can also contain 
placeholders as
 defined in @code{TeX-expand-list} which are expanded before the viewer
 is called.
 
+The third element of each item is a string, or a list of strings, with
+the name of the executable, or executables, needed to open the output
+file in the viewer.  Placeholders defined in @code{TeX-expand-list} can
+be used here.  This element is optional and is used to check whether the
+viewer is actually available on the system.
+
 A built-in viewer spec from @code{TeX-view-program-list-builtin} can be
 overwritten by defining a new viewer spec with the same name.
 @end defopt
diff --git a/doc/changes.texi b/doc/changes.texi
index 0dd30bd..a4b2e76 100644
--- a/doc/changes.texi
+++ b/doc/changes.texi
@@ -14,6 +14,10 @@
 @item
 New option @code{TeX-file-line-error} allows to select file:line:error
 style for error messages.
+
address@hidden
address@hidden can contain, as third optional element of
+each item, the name of the executable(s) needed to open the viewer.
 @end itemize
 
 @heading News in 11.88
diff --git a/tex.el b/tex.el
index 3b530cb..b422ed1 100644
--- a/tex.el
+++ b/tex.el
@@ -1128,14 +1128,14 @@ the requirements are met."
 (defvar TeX-view-program-list-builtin
   (cond
    ((eq system-type 'windows-nt)
-    '(("Yap" ("yap -1" (mode-io-correlate " -s %n%b") " %o"))
-      ("dvips and start" "dvips %d -o && start \"\" %f")
-      ("start" "start \"\" %o")))
+    '(("Yap" ("yap -1" (mode-io-correlate " -s %n%b") " %o") "yap")
+      ("dvips and start" "dvips %d -o && start \"\" %f" ,(list "dvips" 
"start"))
+      ("start" "start \"\" %o" "start")))
    ((eq system-type 'darwin)
-    '(("Preview.app" "open -a Preview.app %o")
-      ("Skim" "open -a Skim.app %o")
-      ("displayline" "displayline %n %o %b")
-      ("open" "open %o")))
+    '(("Preview.app" "open -a Preview.app %o" "open")
+      ("Skim" "open -a Skim.app %o" "open")
+      ("displayline" "displayline %n %o %b" "displayline")
+      ("open" "open %o" "open")))
    (t
     `(("xdvi" ("%(o?)xdvi"
               (mode-io-correlate " -sourceposition \"%n %b\" -editor \"%cS\"")
@@ -1147,10 +1147,10 @@ the requirements are met."
               (paper-letter " -paper us")
               (paper-legal " -paper legal")
               (paper-executive " -paper 7.25x10.5in")
-              " %d"))
-      ("dvips and gv" "%(o?)dvips %d -o && gv %f")
-      ("gv" "gv %o")
-      ("xpdf" ("xpdf -remote %s -raise %o" (mode-io-correlate " %(outpage)")))
+              " %d") "%(o?)xdvi")
+      ("dvips and gv" "%(o?)dvips %d -o && gv %f" ,(list "%(o?)dvips" "gv"))
+      ("gv" "gv %o" "gv")
+      ("xpdf" ("xpdf -remote %s -raise %o" (mode-io-correlate " %(outpage)")) 
"xpdf")
       ("Evince" ,(if (TeX-evince-dbus-p :forward)
                     'TeX-evince-sync-view
                   `("evince" (mode-io-correlate
@@ -1159,9 +1159,9 @@ the requirements are met."
                               ,(if (string-match "--page-index"
                                                  (shell-command-to-string 
"evince --help"))
                                    " -i %(outpage)"
-                                 " -p %(outpage)")) " %o")))
-      ("Okular" ("okular --unique %o" (mode-io-correlate "#src:%n%a")))
-      ("xdg-open" "xdg-open %o"))))
+                                 " -p %(outpage)")) " %o")) "evince")
+      ("Okular" ("okular --unique %o" (mode-io-correlate "#src:%n%a")) 
"okular")
+      ("xdg-open" "xdg-open %o"))) "xdg-open")
   "Alist of built-in viewer specifications.
 This variable should not be changed by the user who can use
 `TeX-view-program-list' to add new viewers or overwrite the
@@ -1169,7 +1169,7 @@ definition of built-in ones.  The latter variable also 
contains a
 description of the data format.")
 
 (defcustom TeX-view-program-list nil
-  "Alist of viewer specifications.
+  "List of viewer specifications.
 This variable can be used to specify how a viewer is to be
 invoked and thereby add new viewers on top of the built-in list
 of viewers defined in `TeX-view-program-list-builtin' or override
@@ -1188,6 +1188,12 @@ the command line parts.  Parts with a predicate are only
 considered if the predicate was evaluated with a positive result.
 Note that the command line can contain placeholders as defined in
 `TeX-expand-list' which are expanded before the viewer is called.
+The third element of the item is optional and is a string, or a
+list of strings, with the name of the executable, or executables,
+needed to open the output file in the viewer.  Placeholders
+defined in `TeX-expand-list' can be used here.  This element is
+used to check whether the viewer is actually available on the
+system.
 
 The use of a function as the second element only works if the
 View command in `TeX-command-list' makes use of the hook
@@ -1198,35 +1204,39 @@ show up in the customization interface for this 
variable after
 restarting Emacs."
   :group 'TeX-view
   :type
-  `(alist
-    :key-type (string :tag "Name")
-    :value-type
-    (choice
-     (group :tag "Command" (string :tag "Command"))
-     (group :tag "Command parts"
-           (repeat
-            :tag "Command parts"
-            (choice
-             (string :tag "Command part")
-             (list :tag "Predicate and command part"
-                   ,(let (list)
-                      ;; Build the list of available predicates.
-                      (mapc (lambda (spec)
-                              (add-to-list 'list `(const ,(car spec))))
-                            (append TeX-view-predicate-list
-                                    TeX-view-predicate-list-builtin))
-                      ;; Sort the list alphabetically.
-                      (setq list (sort list
-                                       (lambda (a b)
-                                         (string<
-                                          (downcase (symbol-name (cadr a)))
-                                          (downcase (symbol-name (cadr b)))))))
-                      `(choice
-                        (choice :tag "Predicate" ,@list)
-                        (repeat :tag "List of predicates"
-                                (choice :tag "Predicate" ,@list))))
-                   (string :tag "Command part")))))
-     (group :tag "Function" function))))
+  `(repeat
+    (list
+     (string :tag "Name")
+     (choice
+      (group :tag "Command" (string :tag "Command"))
+      (group :tag "Command parts"
+            (repeat
+             :tag "Command parts"
+             (choice
+              (string :tag "Command part")
+              (list :tag "Predicate and command part"
+                    ,(let (list)
+                       ;; Build the list of available predicates.
+                       (mapc (lambda (spec)
+                               (add-to-list 'list `(const ,(car spec))))
+                             (append TeX-view-predicate-list
+                                     TeX-view-predicate-list-builtin))
+                       ;; Sort the list alphabetically.
+                       (setq list (sort list
+                                        (lambda (a b)
+                                          (string<
+                                           (downcase (symbol-name (cadr a)))
+                                           (downcase (symbol-name (cadr 
b)))))))
+                       `(choice
+                         (choice :tag "Predicate" ,@list)
+                         (repeat :tag "List of predicates"
+                                 (choice :tag "Predicate" ,@list))))
+                    (string :tag "Command part")))))
+      (group :tag "Function" function))
+     (choice :tag "Viewer executable(s)"
+            (string :tag "One executable")
+            (repeat :tag "List of executables" (string :tag "Name"))
+            (const :tag "No executable" nil)))))
 
 ;; XXX: Regarding a possibility to (manually) run an update command,
 ;; one could support this through `TeX-view' by letting it temporarily
@@ -1319,16 +1329,31 @@ predicates are true, nil otherwise."
 (defun TeX-view-command-raw ()
   "Choose a viewer and return its unexpanded command string."
   (let ((selection TeX-view-program-selection)
-       entry viewer spec command)
+       entry viewer item executable spec command)
     ;; Find the appropriate viewer.
     (while (and (setq entry (pop selection)) (not viewer))
       (when (TeX-view-match-predicate (car entry))
        (setq viewer (cadr entry))))
     (unless viewer
       (error "No matching viewer found"))
-    ;; Get the command line or function spec.
-    (setq spec (cadr (assoc viewer (append TeX-view-program-list
-                                          TeX-view-program-list-builtin))))
+    (setq item (assoc viewer (append TeX-view-program-list
+                                    TeX-view-program-list-builtin))
+         ;; Get the command line or function spec.
+         spec (cadr item)
+         ;; Get the name of the executable(s) associated to the viewer.
+         executable (nth 2 item))
+    ;; Check the executable exists.
+    (unless (or (null executable)
+               (cond
+                ((stringp executable)
+                 (executable-find (TeX-command-expand executable nil)))
+                ((listp executable)
+                 (catch 'notfound
+                   (dolist (exec executable t)
+                     (unless (executable-find (TeX-command-expand exec nil))
+                       (throw 'notfound nil)))))))
+      (error (format "Cannot find %S viewer.  \
+Select another one in `TeX-view-program-selection'" viewer)))
     (cond ((functionp spec)
           ;; Converting the function call to a string is ugly, but
           ;; the backend currently only supports strings.
@@ -1338,7 +1363,7 @@ predicates are true, nil otherwise."
          ((null spec)
           (error
            (format "Unknown %S viewer. \
-Check the `TeX-view-program-selection' variable." viewer)))
+Check the `TeX-view-program-selection' variable" viewer)))
          (t
           ;; Build the unexpanded command line.  Pieces with predicates are
           ;; only added if the predicate is evaluated positively.