Consider electric-pair-mode in tex-mode.

Fixes: debbugs:19356

* lisp/textmodes/tex-mode.el (tex-insert-quote): Consider and respect
`electric-pair-mode'.

* test/automated/electric-tests.el (autowrapping-7): New test for
tex-mode's autowrapping.
(electric-pair-test-for): Call the actual key-binding
interactively.

2 files changed, 45 insertions, 10 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 4be07b5921c..204283ea705 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2014-12-14  João Távora  <joaotavora@gmail.com>
+
+        * textmodes/tex-mode.el (tex-insert-quote): Consider and respect
+        `electric-pair-mode' (bug#19356).
+
 2014-12-12  Michael Albinus  <michael.albinus@gmx.de>
 
         * simple.el (password-word-equivalents): Add "passcode", used for
diff --git a/lisp/textmodes/tex-mode.el b/lisp/textmodes/tex-mode.el
index 18843bcd15a..cb8f2ee4357 100644
--- a/lisp/textmodes/tex-mode.el
+++ b/lisp/textmodes/tex-mode.el
@@ -1277,18 +1277,48 @@ Inserts the value of `tex-open-quote' (normally ``) or `tex-close-quote'
 \(normally '') depending on the context.  With prefix argument, always
 inserts \" characters."
   (interactive "*P")
+  ;; Discover if we'll be inserting normal double quotes.
+  ;;
   (if (or arg (memq (char-syntax (preceding-char)) '(?/ ?\\))
-          (eq (get-text-property (point) 'face) 'tex-verbatim)
-          (save-excursion
-            (backward-char (length tex-open-quote))
-            (when (or (looking-at (regexp-quote tex-open-quote))
-                      (looking-at (regexp-quote tex-close-quote)))
-              (delete-char (length tex-open-quote))
-              t)))
+          (eq (get-text-property (point) 'face) 'tex-verbatim)
+          ;; Discover if a preceding occurance of `tex-open-quote'
+          ;; should be morphed to a normal double quote.
+          ;;
+          (and (>= (point) (+ (point-min) (length tex-open-quote)))
+               (save-excursion
+                 (backward-char (length tex-open-quote))
+                 (when (or (looking-at (regexp-quote tex-open-quote))
+                           (looking-at (regexp-quote tex-close-quote)))
+                   (delete-char (length tex-open-quote))
+                   (when (looking-at (regexp-quote tex-close-quote))
+                     (delete-char (length tex-close-quote)))
+                   t))))
+      ;; Insert the normal quote (eventually letting
+      ;; `electric-pair-mode' do its thing).
+      ;;
       (self-insert-command (prefix-numeric-value arg))
-    (insert (if (or (memq (char-syntax (preceding-char)) '(?\( ?> ?\s))
-                    (memq (preceding-char) '(?~)))
-                tex-open-quote tex-close-quote))))
+    ;; We'll be inserting fancy TeX quotes, but consider and imitate
+    ;; `electric-pair-mode''s two behaviours: pair-insertion and
+    ;; region wrapping.
+    ;;
+    (if (and electric-pair-mode (use-region-p))
+        (let* ((saved (point-marker)))
+          (goto-char (mark))
+          (insert (if (> saved (mark)) tex-open-quote tex-close-quote))
+          (goto-char saved)
+          (insert (if (> saved (mark)) tex-close-quote tex-open-quote)))
+      (if (or (memq (char-syntax (preceding-char)) '(?\( ?> ?\s))
+              (memq (preceding-char) '(?~)))
+          (if electric-pair-mode
+              (if (looking-at (regexp-quote tex-close-quote))
+                  (forward-char (length tex-close-quote))
+                (insert tex-open-quote)
+                (insert tex-close-quote)
+                (backward-char (length tex-close-quote)))
+            (insert tex-open-quote))
+        (if (looking-at (regexp-quote tex-close-quote))
+            (forward-char (length tex-close-quote))
+          (insert tex-close-quote))))))
 
 (defun tex-validate-buffer ()
   "Check current buffer for paragraphs containing mismatched braces or $s.