[elpa] externals/auctex f52479b 11/26: Improve checking of a TeX distribution and make it optional

[Tassilo Horn]

branch: externals/auctex
commit f52479b816c0e6097293221b8488144cbdea9123
Author: Mosè Giordano <address@hidden>
Commit: Mosè Giordano <address@hidden>

    Improve checking of a TeX distribution and make it optional
    
    * tex-buf.el (TeX-check-TeX, TeX-check-TeX-command-not-found): New
    customizable options.
    (TeX-command): Do a better check for the presence of a TeX
    distribution.  Run `call-process' instead of `executable-find',
    like `TeX-run-command' actually does.  The point is that
    `call-process' and `start-process' use `PATH' environment
    variable, `executable-find' uses `exec-path' variable and they do
    not need to match, but we should check what `TeX-run-command' will
    really do.
    
    * doc/auctex.texi (Processor Options): Document `TeX-check-TeX'.
    
    * doc/changes.texi: Mention `TeX-check-TeX'.
---
 ChangeLog        |   16 ++++++++++++++++
 doc/auctex.texi  |   17 +++++++++++++++++
 doc/changes.texi |   10 +++++++---
 tex-buf.el       |   17 +++++++++++++++--
 4 files changed, 55 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 6d8a74b..387c136 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+2015-11-06  Mos� Giordano  <address@hidden>
+
+       * tex-buf.el (TeX-check-TeX, TeX-check-TeX-command-not-found): New
+       customizable options.
+       (TeX-command): Do a better check for the presence of a TeX
+       distribution.  Run `call-process' instead of `executable-find',
+       like `TeX-run-command' actually does.  The point is that
+       `call-process' and `start-process' use `PATH' environment
+       variable, `executable-find' uses `exec-path' variable and they do
+       not need to match, but we should check what `TeX-run-command' will
+       really do.
+
+       * doc/auctex.texi (Processor Options): Document `TeX-check-TeX'.
+
+       * doc/changes.texi: Mention `TeX-check-TeX'.
+
 2015-11-03  Mos� Giordano  <address@hidden>
 
        * doc/auctex.texi (Processor Options): Document
diff --git a/doc/auctex.texi b/doc/auctex.texi
index 6489c44..4b0f001 100644
--- a/doc/auctex.texi
+++ b/doc/auctex.texi
@@ -2989,6 +2989,23 @@ command can either be a variable or a string.  An empty 
string or nil
 means there is no command available.
 @end defopt
 
+In some systems, Emacs cannot inherit the PATH environment variable from
+the shell and thus @AUCTeX{} may not be able to run @TeX{} commands.
+Before running them, @AUCTeX{} checks if it able to find those commands
+and will warn you in case it fails.  You can skip this test by changing
+the option @code{TeX-check-TeX}.
+
address@hidden TeX-check-TeX
address@hidden TeX-command
address@hidden TeX-check-TeX-command-not-found
+If non-nil, @AUCTeX{} will check if it is able to find a working @TeX{}
+distribution before running @TeX{}, @LaTeX{}, @ConTeXt{}, etc.  It
+actually checks if can run @code{TeX-command} command or the shell
+returns a command not found error.  The error code returned by the shell
+in this case can be set in @code{TeX-check-TeX-command-not-found}
+option.
address@hidden defopt
+
 Some @LaTeX{} packages requires the document to be compiled with a
 specific engine.  Notable examples are fontspec and polyglossia
 packages, which require address@hidden and address@hidden engines.  If you try 
to
diff --git a/doc/changes.texi b/doc/changes.texi
index ed3ad01..fb927f6 100644
--- a/doc/changes.texi
+++ b/doc/changes.texi
@@ -56,9 +56,13 @@ built-in expanders.  You might want to keep in 
@code{TeX-expand-list}
 only new expansion strings.
 
 @item
-When new option @code{TeX-check-engine} is non-nil, before running
address@hidden commands @AUCTeX{} will check whether the correct engine has
-been set, based upon known restrictions posed by @LaTeX{} packages.
+Before running commands like @TeX{} and @LaTeX{}, now @AUCTeX{} performs
+some checks.  If @code{TeX-check-TeX} is non-nil, it will test whether a
+working @TeX{} distribution is actually present in the system and
+available to Emacs.  Instead, when @code{TeX-check-engine} is non-nil,
+before running @LaTeX{} commands @AUCTeX{} will check whether the
+correct engine has been set, based upon known restrictions posed by
address@hidden packages.
 
 @item
 Basic support to @ConTeXt{} Mark IV has been added.  Users can now
diff --git a/tex-buf.el b/tex-buf.el
index ec3653c..61a61ad 100644
--- a/tex-buf.el
+++ b/tex-buf.el
@@ -437,6 +437,16 @@ Do you want to select one of these engines?"
         (add-file-local-variable 'TeX-engine engine)
         (save-buffer))))))
 
+(defcustom TeX-check-TeX t
+  "Whether AUCTeX should check if a working TeX distribution is present."
+  :group 'TeX-command
+  :type 'boolean)
+
+(defcustom TeX-check-TeX-command-not-found 127
+  "Numerical code returned by shell for a command not found error."
+  :group 'TeX-command
+  :type 'integer)
+
 (defun TeX-command (name file &optional override-confirm)
   "Run command NAME on the file returned by calling FILE.
 
@@ -481,8 +491,11 @@ been set."
 
     ;; Before running some commands, check that AUCTeX is able to find "tex"
     ;; program.
-    (and (member name '("TeX" "LaTeX" "AmSTeX" "ConTeXt" "ConTeXt Full"))
-        (not (executable-find TeX-command))
+    (and TeX-check-TeX
+         (member name '("TeX" "LaTeX" "AmSTeX" "ConTeXt" "ConTeXt Full"))
+        (= TeX-check-TeX-command-not-found
+            (call-process TeX-shell nil nil nil
+                          TeX-shell-command-option TeX-command))
         (error (format "ERROR: AUCTeX cannot find a working TeX distribution.
 Make sure you have one and that TeX binaries are in PATH environment 
variable%s"
                        (if (eq system-type 'darwin)