[LyX/master] Fix bug #9112: There is a test here that seems intended to catch the case where there are unbalanced braces, but it comes too late. In that case, we try to check cmd[docstring::npos] and crash.

[Richard Heck]

commit 6b0a8fbc9614433e7db4e6f994fd62886da8b8eb
Author: Richard Heck <rgh...@lyx.org>
Date:   Thu May 8 18:19:55 2014 -0400

    Fix bug #9112: There is a test here that seems intended to catch the
    case where there are unbalanced braces, but it comes too late. In that
    case, we try to check cmd[docstring::npos] and crash.

diff --git a/src/Encoding.cpp b/src/Encoding.cpp
index a231106..bc27675 100644
--- a/src/Encoding.cpp
+++ b/src/Encoding.cpp
@@ -537,8 +537,11 @@ docstring Encodings::fromLaTeXCommand(docstring const & 
cmd, int cmdtype,
                if (j + 1 < cmdend && cmd[j + 1] == '{') {
                        size_t k = j + 1;
                        int count = 1;
-                       while (k < cmdend && count && k != docstring::npos) {
+                       while (k < cmdend && count) {
                                k = cmd.find_first_of(from_ascii("{}"), k + 1);
+                               // braces may not be balanced
+                               if (k == docstring::npos)
+                                       break;
                                if (cmd[k] == '{')
                                        ++count;
                                else
@@ -603,8 +606,11 @@ docstring Encodings::fromLaTeXCommand(docstring const & 
cmd, int cmdtype,
                            k < cmdend && cmd[k] == '{') {
                                size_t l = k;
                                int count = 1;
-                               while (l < cmdend && count && l != 
docstring::npos) {
+                               while (l < cmdend && count) {
                                        l = cmd.find_first_of(from_ascii("{}"), 
l + 1);
+                                       // braces may not be balanced
+                                       if (l == docstring::npos)
+                                               break;
                                        if (cmd[l] == '{')
                                                ++count;
                                        else