CppEditor: Fix folding after comment

Fixes: QTCREATORBUG-5110
Change-Id: I65e0245d68ed41ab0cfc85cedbee21584b6fa90f
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/cppeditor/cpphighlighter.cpp

@@ -81,8 +81,6 @@ void CppHighlighter::highlightBlock(const QString &text)
         return;
     }
 
-    const int firstNonSpace = tokens.first().utf16charsBegin();
-
     // Keep "semantic parentheses".
     Parentheses parentheses;
     if (TextBlockUserData *userData = TextDocumentLayout::textUserData(currentBlock())) {
@@ -121,9 +119,16 @@ void CppHighlighter::highlightBlock(const QString &text)
             if (tk.is(T_LBRACE)) {
                 ++braceDepth;
 
-                // if a folding block opens at the beginning of a line, treat the entire line
-                // as if it were inside the folding block
-                if (tk.utf16charsBegin() == firstNonSpace) {
+                // if a folding block opens at the beginning of a line, treat the line before
+                // as if it were inside the folding block except if it is a comment or the line does
+                // end with ;
+                const int firstNonSpace = tokens.first().utf16charsBegin();
+                const QString prevBlockText = currentBlock().previous().isValid()
+                                                  ? currentBlock().previous().text().trimmed()
+                                                  : QString();
+                if (!prevBlockText.isEmpty() && !prevBlockText.startsWith("//")
+                    && !prevBlockText.endsWith("*/") && !prevBlockText.endsWith(";")
+                    && tk.utf16charsBegin() == firstNonSpace) {
                     ++foldingIndent;
                     TextDocumentLayout::userData(currentBlock())->setFoldingStartIncluded(true);
                 }
@@ -653,6 +658,32 @@ void CppHighlighterTest::testParentheses()
     QCOMPARE(TextDocumentLayout::parentheses(block).count(), expectedParenCount);
 }
 
+void CppHighlighterTest::testFoldingIndent_data()
+{
+    QTest::addColumn<int>("line");
+    QTest::addColumn<int>("expectedFoldingIndent");
+    QTest::addColumn<int>("expectedFoldingIndentNextLine");
+
+    QTest::newRow("braces after one line comment") << 52 << 0 << 1;
+    QTest::newRow("braces after multiline comment") << 59 << 0 << 1;
+    QTest::newRow("braces after completed line") << 67 << 1 << 2;
+}
+
+void CppHighlighterTest::testFoldingIndent()
+{
+    QFETCH(int, line);
+    QFETCH(int, expectedFoldingIndent);
+    QFETCH(int, expectedFoldingIndentNextLine);
+
+    QTextBlock block = m_doc.findBlockByNumber(line - 1);
+    QVERIFY(block.isValid());
+    QCOMPARE(TextDocumentLayout::foldingIndent(block), expectedFoldingIndent);
+
+    QTextBlock nextBlock = m_doc.findBlockByNumber(line);
+    QVERIFY(nextBlock.isValid());
+    QCOMPARE(TextDocumentLayout::foldingIndent(nextBlock), expectedFoldingIndentNextLine);
+}
+
 } // namespace Internal
 #endif // WITH_TESTS
 

src/plugins/cppeditor/cpphighlighter.h

@@ -54,6 +54,8 @@ private slots:
     void test();
     void testParentheses_data();
     void testParentheses();
+    void testFoldingIndent_data();
+    void testFoldingIndent();
 
 private:
     QTextDocument m_doc;

src/plugins/cppeditor/testcases/highlightingtestcase.cpp

@@ -47,3 +47,24 @@ static void parenTest()
 
 const char* s7 = R"(
 ))";
+
+// comment
+{
+
+}
+
+/*
+ *
+ */
+{
+
+}
+
+static void parenTest2()
+{
+
+    parenTest();
+    {
+
+    }
+}