CppTools: Do not indent within string literals

Multi-line strings must be kept as the user wrote them.

Fixes: QTCREATORBUG-20180
Change-Id: I141eff52b55d31215e6f5c6c5a0e026689db877a
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/cpptools/cppcodeformatter.cpp

@@ -635,7 +635,6 @@ void CodeFormatter::updateStateUntil(const QTextBlock &endBlock)
             break;
         if (loadLexerState(it) == -1)
             break;
-
         previousState = blockData.m_endState;
     }
 
@@ -673,6 +672,16 @@ void CodeFormatter::updateLineStateChange(const QTextBlock &block)
     saveBlockData(&next, BlockData());
 }
 
+bool CodeFormatter::isInStringLiteral(const QTextBlock &block) const
+{
+    if (!block.previous().isValid())
+        return false;
+    BlockData blockData;
+    if (!loadBlockData(block.previous(), &blockData))
+        return false;
+    return !blockData.m_endState.isEmpty() && blockData.m_endState.top().type == string_open;
+}
+
 CodeFormatter::State CodeFormatter::state(int belowTop) const
 {
     if (belowTop < m_currentState.size())

src/plugins/cpptools/cppcodeformatter.h

@@ -57,6 +57,7 @@ public:
     // calculates the state change introduced by changing a single line
     void updateLineStateChange(const QTextBlock &block);
 
+    bool isInStringLiteral(const QTextBlock &block) const;
     void indentFor(const QTextBlock &block, int *indent, int *padding);
     void indentForNewLineAfter(const QTextBlock &block, int *indent, int *padding);
 

src/plugins/cpptools/cppqtstyleindenter.cpp

@@ -99,6 +99,8 @@ void CppQtStyleIndenter::indentBlock(const QTextBlock &block,
     QtStyleCodeFormatter codeFormatter(tabSettings, codeStyleSettings());
 
     codeFormatter.updateStateUntil(block);
+    if (codeFormatter.isInStringLiteral(block))
+        return;
     int indent;
     int padding;
     codeFormatter.indentFor(block, &indent, &padding);
@@ -135,10 +137,12 @@ void CppQtStyleIndenter::indent(const QTextCursor &cursor,
         QTextCursor tc = cursor;
         tc.beginEditBlock();
         do {
+            if (!codeFormatter.isInStringLiteral(block)) {
                 int indent;
                 int padding;
                 codeFormatter.indentFor(block, &indent, &padding);
                 tabSettings.indentLine(block, indent + padding, padding);
+            }
             codeFormatter.updateLineStateChange(block);
             block = block.next();
         } while (block.isValid() && block != end);