Fix single line comment logic.
It seems reasonable to check that langDef.mSingleLineComment is
non-empty before trying to match it with the current line of code.
diff --git a/TextEditor.cpp b/TextEditor.cpp
index 1492dcd..97b373b 100644
--- a/TextEditor.cpp
+++ b/TextEditor.cpp
@@ -1924,7 +1924,8 @@
auto from = line.begin() + currentCoord.mColumn;
auto& startStr = mLanguageDefinition.mCommentStart;
auto& singleStartStr = mLanguageDefinition.mSingleLineComment;
- if (currentCoord.mColumn + singleStartStr.size() <= line.size() &&
+ if (singleStartStr.size() > 0 &&
+ currentCoord.mColumn + singleStartStr.size() <= line.size() &&
equals(singleStartStr.begin(), singleStartStr.end(), from, from + singleStartStr.size(), pred))
withinSingleLineComment = true;
else if (!withinSingleLineComment && currentCoord.mColumn + startStr.size() <= line.size() &&
