Backport: Fix bug with regular expression searches failing to match at line start or end.

This was a work-around for infinite loops when replacing empty matches and this
is now the application's responsibility.

Backport of changeset 6683:bcae0331720b.

2 files changed, 12 insertions, 16 deletions

diff --git a/doc/ScintillaHistory.html b/doc/ScintillaHistory.html
index a0fc4f2b6..6e41fbb67 100644
--- a/doc/ScintillaHistory.html
+++ b/doc/ScintillaHistory.html
@@ -543,6 +543,14 @@
 	when text insertion followed by caret up or down.
 	</li>
 	<li>
+	Bugs fixed in regular expression searches in Scintilla where some matches did not occur in an
+	effort to avoid infinite loops when replacing on empty matches like "^" and "$".
+	Applications should always handle empty matches in a way that avoids infinite loops, commonly
+	by incrementing the search position after replacing an empty match.
+	SciTE fixes a bug where replacing "^" always matched on the first line even when it was an
+	"in selection" replace and the selection started after the line start.
+	</li>
+	<li>
 	On Win32, a new file, ScintillaDLL.cxx, provides
 	the DllMain function required for a stand-alone Scintilla DLL. Build and project files should include this
 	file when producing a DLL and omit it when producing a static library or linking Scintilla statically.
diff --git a/src/Document.cxx b/src/Document.cxx
index 1d77f7065..1c9b1ceda 100644
--- a/src/Document.cxx
+++ b/src/Document.cxx
@@ -2537,25 +2537,13 @@ public:
 	RESearchRange(const Document *doc_, Sci::Position minPos, Sci::Position maxPos) : doc(doc_) {
 		increment = (minPos <= maxPos) ? 1 : -1;
 
-		// Range endpoints should not be inside DBCS characters, but just in case, move them.
-		startPos = doc->MovePositionOutsideChar(minPos, 1, false);
-		endPos = doc->MovePositionOutsideChar(maxPos, 1, false);
+		// Range endpoints should not be inside DBCS characters or between a CR and LF,
+		// but just in case, move them.
+		startPos = doc->MovePositionOutsideChar(minPos, 1, true);
+		endPos = doc->MovePositionOutsideChar(maxPos, 1, true);
 
 		lineRangeStart = static_cast<Sci::Line>(doc->LineFromPosition(startPos));
 		lineRangeEnd = static_cast<Sci::Line>(doc->LineFromPosition(endPos));
-		if ((increment == 1) &&
-			(startPos >= doc->LineEnd(lineRangeStart)) &&
-			(lineRangeStart < lineRangeEnd)) {
-			// the start position is at end of line or between line end characters.
-			lineRangeStart++;
-			startPos = static_cast<Sci::Position>(doc->LineStart(lineRangeStart));
-		} else if ((increment == -1) &&
-			(startPos <= doc->LineStart(lineRangeStart)) &&
-			(lineRangeStart > lineRangeEnd)) {
-			// the start position is at beginning of line.
-			lineRangeStart--;
-			startPos = static_cast<Sci::Position>(doc->LineEnd(lineRangeStart));
-		}
 		lineRangeBreak = lineRangeEnd + increment;
 	}
 	Range LineRange(Sci::Line line) const {