Editor: Fixed endless loop in BaseTextFind

...when trying to replace some regular expressions that could result in
empty search results like ^, $ or \b.

Task-number: QTCREATORBUG-8464
Change-Id: I91a304d3609c3ec20437c698d53e6a1819dfb924
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>

1 files changed, 17 insertions, 3 deletions

diff --git a/src/plugins/find/basetextfind.cpp b/src/plugins/find/basetextfind.cpp
index 5bcdb2835f5..df55f136c94 100644
--- a/src/plugins/find/basetextfind.cpp
+++ b/src/plugins/find/basetextfind.cpp
@@ -264,9 +264,23 @@ int BaseTextFind::replaceAll(const QString &before, const QString &after,
     regexp.setPatternSyntax(usesRegExp ? QRegExp::RegExp : QRegExp::FixedString);
     regexp.setCaseSensitivity((findFlags & Find::FindCaseSensitively) ? Qt::CaseSensitive : Qt::CaseInsensitive);
     QTextCursor found = findOne(regexp, editCursor, Find::textDocumentFlagsForFindFlags(findFlags));
-    while (!found.isNull()
-           && (found.selectionStart() < found.selectionEnd() || after.length() > 0)
-           && inScope(found.selectionStart(), found.selectionEnd())) {
+    bool first = true;
+    while (!found.isNull() && inScope(found.selectionStart(), found.selectionEnd())) {
+        if (found == editCursor && !first) {
+            if (editCursor.atEnd())
+                break;
+            // If the newly found QTextCursor is the same as recently edit one we have to move on,
+            // otherwise we would run into an endless loop for some regular expressions
+            // like ^ or \b.
+            QTextCursor newPosCursor = editCursor;
+            newPosCursor.movePosition(findFlags & Find::FindBackward ?
+                                          QTextCursor::PreviousCharacter :
+                                          QTextCursor::NextCharacter);
+            found = findOne(regexp, newPosCursor, Find::textDocumentFlagsForFindFlags(findFlags));
+            continue;
+        }
+        if (first)
+            first = false;
         ++count;
         editCursor.setPosition(found.selectionStart());
         editCursor.setPosition(found.selectionEnd(), QTextCursor::KeepAnchor);