qmlls: check user-supplied names on renaming

Implement the checking of user-supplied names for renaming operations
in QmlLSUtils and qqmlrenamesymbolsupport.cpp

Add a helper method QQmlLSUtils::isValidEcmaScriptIdentifier that runs
the lexer on an identifier. Reject identifiers that do not parse as
T_IDENTIFIER, like keywords and invalid unicode escapes, for example.

Extend QQmlLSUtilsExpressionType to contain the name of the current
object.

Drive-by change: fix a off-by-one bug in the lexer, where files (or
identifiers, in this case) could not be lexed when they were ending with
an unicode-sequence.

Also, do not crash on JSIdentifiers without semantic scope in
resolveIdentifierExpressionType.

Add some tests, and fix a warning about positionAfterOneIndent
not being used in tst_qmlls_modules.cpp.

Add QQmlLSUtils::isChangedSignalName next to
QQmlLSUtils::isChangedHandlerName, and QQmlLSUtils::isHandlerName
and add tests for all three.

Fixes: QTBUG-114951
Task-number: QTBUG-114788
Change-Id: I0f1a544b70dfb69bca4aef355a8a8658f1d23081
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/qml/parser/qqmljslexer.cpp b/src/qml/parser/qqmljslexer.cpp
index 28f4684649..704c7eb00d 100644
--- a/src/qml/parser/qqmljslexer.cpp
+++ b/src/qml/parser/qqmljslexer.cpp
@@ -368,7 +368,8 @@ uint Lexer::decodeUnicodeEscapeCharacter(bool *ok)
 {
     Q_ASSERT(_state.currentChar == u'u');
     scanChar(); // skip u
-    if (_codePtr + 4 <= _endPtr && isHexDigit(_state.currentChar)) {
+    constexpr int distanceFromFirstHexToLastHex = 3;
+    if (_codePtr + distanceFromFirstHexToLastHex <= _endPtr && isHexDigit(_state.currentChar)) {
         uint codePoint = 0;
         for (int i = 0; i < 4; ++i) {
             int digit = hexDigit(_state.currentChar);