fix crash when modifiying some project files with scopes

TokBranch may hold zero-sized blocks, which must be explicitly handled
before trying to enter them.

Task-number: QTCREATORBUG-7706
Change-Id: Idaa129e12eb89cbc9572277083765fa6e15e0849
Reviewed-by: Daniel Teske <daniel.teske@nokia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@nokia.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/src/shared/proparser/prowriter.cpp b/src/shared/proparser/prowriter.cpp
index 6a6b6f0678..e70740efd9 100644
--- a/src/shared/proparser/prowriter.cpp
+++ b/src/shared/proparser/prowriter.cpp
@@ -325,11 +325,15 @@ static void findProVariables(const ushort *tokPtr, const QStringList &vars,
     while (ushort tok = *tokPtr++) {
         if (tok == TokBranch) {
             uint blockLen = getBlockLen(tokPtr);
-            findProVariables(tokPtr, vars, proVars, lineNo);
-            tokPtr += blockLen;
+            if (blockLen) {
+                findProVariables(tokPtr, vars, proVars, lineNo);
+                tokPtr += blockLen;
+            }
             blockLen = getBlockLen(tokPtr);
-            findProVariables(tokPtr, vars, proVars, lineNo);
-            tokPtr += blockLen;
+            if (blockLen) {
+                findProVariables(tokPtr, vars, proVars, lineNo);
+                tokPtr += blockLen;
+            }
         } else if (tok == TokAssign || tok == TokAppend || tok == TokAppendUnique) {
             if (getLiteral(lastXpr, tokPtr - 1, tmp) && vars.contains(tmp))
                 *proVars << lineNo;