Bug [#2405]. Fix regular expression bug in reverse direction where shortened

match returned.

4 files changed, 22 insertions, 23 deletions

diff --git a/cppcheck.suppress b/cppcheck.suppress
index 5e404b6df..092de64ee 100644
--- a/cppcheck.suppress
+++ b/cppcheck.suppress
@@ -85,8 +85,6 @@ passedByValue
 // Checks for moves move to variables that are not read but the moved from is checked

 unreadVariable:scintilla/test/unit/*.cxx

 accessMoved:scintilla/test/unit/*.cxx

-// Temporary code for test that fails

-redundantAssignment:scintilla/test/unit/testDocument.cxx

 

 // cppcheck fails REQUIRE from Catch

 comparisonOfFuncReturningBoolError:scintilla/test/unit/*.cxx

diff --git a/doc/ScintillaHistory.html b/doc/ScintillaHistory.html
index dc2a8415e..ca780bc46 100644
--- a/doc/ScintillaHistory.html
+++ b/doc/ScintillaHistory.html
@@ -618,6 +618,10 @@
 	<a href="https://sourceforge.net/p/scintilla/bugs/2405/">Bug #2405</a>.
 	</li>
 	<li>
+	Fix regular expression bug in reverse direction where shortened match returned.
+	<a href="https://sourceforge.net/p/scintilla/bugs/2405/">Bug #2405</a>.
+	</li>
+	<li>
 	With a document that does not have the SC_DOCUMENTOPTION_TEXT_LARGE option set,
 	allocating more than 2G (calling SCI_ALLOCATE or similar) will now fail with SC_STATUS_FAILURE.
 	</li>
diff --git a/src/Document.cxx b/src/Document.cxx
index e6521df45..dcb087930 100644
--- a/src/Document.cxx
+++ b/src/Document.cxx
@@ -3269,34 +3269,31 @@ Sci::Position BuiltinRegex::FindText(Document *doc, Sci::Position minPos, Sci::P
 		search.SetLineRange(lineStartPos, lineEndPos);
 		int success = search.Execute(di, startOfLine, endOfLine);
 		if (success) {
-			pos = search.bopat[0];
 			// Ensure only whole characters selected
-			search.eopat[0] = doc->MovePositionOutsideChar(search.eopat[0], 1, false);
-			lenRet = search.eopat[0] - search.bopat[0];
+			Sci::Position endPos = doc->MovePositionOutsideChar(search.eopat[0], 1, false);
 			// There can be only one start of a line, so no need to look for last match in line
 			if ((resr.increment == -1) && !searchforLineStart) {
 				// Check for the last match on this line.
-				int repetitions = 1000;	// Break out of infinite loop
-				RESearch::MatchPositions bopat{};
-				RESearch::MatchPositions eopat{};
-				while (success && (search.eopat[0] <= endOfLine) && (repetitions--)) {
-					bopat = search.bopat;
-					eopat = search.eopat;
-					success = search.Execute(di, pos+1, endOfLine);
+				while (success && (endPos < endOfLine)) {
+					const RESearch::MatchPositions bopat = search.bopat;
+					const RESearch::MatchPositions eopat = search.eopat;
+					pos = endPos;
+					if (pos == bopat[0]) {
+						// empty match
+						pos = doc->NextPosition(pos, 1);
+					}
+					success = search.Execute(di, pos, endOfLine);
 					if (success) {
-						if (search.eopat[0] <= minPos) {
-							pos = search.bopat[0];
-							lenRet = search.eopat[0] - search.bopat[0];
-						} else {
-							success = 0;
-						}
+						endPos = doc->MovePositionOutsideChar(search.eopat[0], 1, false);
+					} else {
+						search.bopat = bopat;
+						search.eopat = eopat;
 					}
 				}
-				if (!success) {
-					search.bopat = bopat;
-					search.eopat = eopat;
-				}
 			}
+			search.eopat[0] = endPos;
+			pos = search.bopat[0];
+			lenRet = endPos - pos;
 			break;
 		}
 	}
diff --git a/test/unit/testDocument.cxx b/test/unit/testDocument.cxx
index 52af45167..ba7bb8616 100644
--- a/test/unit/testDocument.cxx
+++ b/test/unit/testDocument.cxx
@@ -517,7 +517,7 @@ TEST_CASE("Document") {
 		REQUIRE(substituted == "\tb\xCE\x93y\n");
 
 		match = doc.FindString(docLength, 0, longest, rePosix);
-		//REQUIRE(match == Match(16, 5));
+		REQUIRE(match == Match(16, 5));
 
 		#ifndef NO_CXX11_REGEX
 		match = doc.FindString(0, docLength, finding, reCxx11);