From f248b6faff0c9fa5eab7bafcc6e2595e2de07071 Mon Sep 17 00:00:00 2001
From: Pavel Sanda <sanda@lyx.org>
Date: Wed, 5 Dec 2007 20:59:11 +0000
Subject: [PATCH] Source highlighting of comments (by Bernhard Reiter)

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/branches/BRANCH_1_5_X@21973 a592a061-630c-0410-9148-cb99ea01b6c8
---
 src/frontends/qt4/QViewSource.cpp | 18 +++++++++++++-----
 status.15x                        |  2 ++
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/frontends/qt4/QViewSource.cpp b/src/frontends/qt4/QViewSource.cpp
index 6c866764cb..32b17103ec 100644
--- a/src/frontends/qt4/QViewSource.cpp
+++ b/src/frontends/qt4/QViewSource.cpp
@@ -139,13 +139,21 @@ void LaTeXHighlighter::highlightBlock(QString const & text)
 		setFormat(index, length, keywordFormat);
 		index = text.indexOf(exprKeyword, index + length);
 	}
-	// comment
-	QRegExp exprComment("(^|[^\\\\])%.*$");
-	index = text.indexOf(exprComment);
+	// %comment
+	// Treat a line as a comment starting at a percent sign
+	// * that is the first character in a line
+	// * that is preceded by 
+	// ** an even number of backslashes
+	// ** any character other than a backslash                   
+	QRegExp exprComment("(?:^|[^\\\\])(?:\\\\\\\\)*(%).*$"); 
+	text.indexOf(exprComment);
+	index = exprComment.pos(1);
 	while (index >= 0) {
-		int const length = exprComment.matchedLength();
+		int const length = exprComment.matchedLength() 
+				 - (index - exprComment.pos(0));
 		setFormat(index, length, commentFormat);
-		index = text.indexOf(exprComment, index + length);
+		text.indexOf(exprComment, index + length);
+		index = exprComment.pos(1);
 	}
 }
 
diff --git a/status.15x b/status.15x
index 1ea948e7c1..a4607e9c70 100644
--- a/status.15x
+++ b/status.15x
@@ -206,6 +206,8 @@ What's new
 
 - Distinguish translations for 'Note' between layouts and inset.
 
+- Fix latex source highlighting of comments
+
 * DOCUMENTATION
 
 - Fix corrupted character in the User's Guide (including the translations).