tildify.el: Fix matched group indexes in end-regex building

* lisp/textmodes/tildifi.el (tildify-find-env): When looking for
a start of an ignore-environment, the regex is built by
concatenating regexes of all the environments configured in
`tildify-ignored-environments-alist'.  So for example, the following
list could be used to match TeX's \verb and \verb* commands:

    (("\\\\verb\\(.\\)" . (1))
     ("\\\\verb\\*\\(.\\)" . (1)))

This would result in the following regex being used to find the start
of any of the variants of the \verb command:

    \\\\verb\\(.\\)\\|\\\\verb\\*\\(.\\)

But now, if “\\\\verb\\*\\(.\\)” matches, the first capture group
won't match anything, and thus (match-string 1) will be nil, which
will cause building of the end-matching regex to fail.

Fix this by using capture groups from the time when the opening
regexes are matched individually.

* tests/automated/tildify-tests.el (tildify-test-find-env-group-index-bug):
New test validating fix to the above bug.

1 files changed, 4 insertions, 0 deletions

diff --git a/test/ChangeLog b/test/ChangeLog
index db32aae578b..93ef0980c9a 100644
--- a/test/ChangeLog
+++ b/test/ChangeLog
@@ -1,5 +1,9 @@
 2014-06-05  Michal Nazarewicz  <mina86@mina86.com>
 
+        * automated/tildify-tests.el (tildify-test-find-env-group-index-bug):
+        New test checking end-regex building when multiple environment pairs
+        use integers to refer to capture groups.
+
         * automated/tildify-tests.el (tildify-test-find-env-end-re-bug): New
         test checking end-regex building in `tildify-find-env' function when
         integers (denoting capture groups) and strings are mixed together.