Markdown writer: don't wrap code block, and detect its end

The end of a code block nested in a list item is now detected;
and if the text of the list item continues after the code block,
it continues to be indented.

Code blocks should never be word-wrapped.

Fixes: QTBUG-80603
Change-Id: I4427f8b1d4807d819616f5cb971e2d006170d9be
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

src/gui/text/qtextmarkdownwriter.cpp

@@ -367,6 +367,14 @@ int QTextMarkdownWriter::writeBlock(const QTextBlock &block, bool wrap, bool ign
     const int ColumnLimit = 80;
     QTextBlockFormat blockFmt = block.blockFormat();
     bool missedBlankCodeBlockLine = false;
+    const bool codeBlock = blockFmt.hasProperty(QTextFormat::BlockCodeFence) ||
+            blockFmt.stringProperty(QTextFormat::BlockCodeLanguage).length() > 0;
+    if (m_fencedCodeBlock && !codeBlock) {
+        m_stream << m_linePrefix << QString(m_wrappedLineIndent, Space)
+                 << m_codeBlockFence << Newline;
+        m_fencedCodeBlock = false;
+        m_codeBlockFence.clear();
+    }
     if (block.textList()) { // it's a list-item
         auto fmt = block.textList()->format();
         const int listLevel = fmt.indent();
@@ -427,7 +435,7 @@ int QTextMarkdownWriter::writeBlock(const QTextBlock &block, bool wrap, bool ign
     } else if (blockFmt.hasProperty(QTextFormat::BlockTrailingHorizontalRulerWidth)) {
         m_stream << "- - -\n"; // unambiguous horizontal rule, not an underline under a heading
         return 0;
-    } else if (blockFmt.hasProperty(QTextFormat::BlockCodeFence) || blockFmt.stringProperty(QTextFormat::BlockCodeLanguage).length() > 0) {
+    } else if (codeBlock) {
         // It's important to preserve blank lines in code blocks.  But blank lines in code blocks
         // inside block quotes are getting preserved anyway (along with the "> " prefix).
         if (!blockFmt.hasProperty(QTextFormat::BlockQuoteLevel))
@@ -442,13 +450,8 @@ int QTextMarkdownWriter::writeBlock(const QTextBlock &block, bool wrap, bool ign
                      << Space << blockFmt.stringProperty(QTextFormat::BlockCodeLanguage) << Newline;
             m_fencedCodeBlock = true;
         }
+        wrap = false;
     } else if (!blockFmt.indent()) {
-        if (m_fencedCodeBlock) {
-            m_stream << m_linePrefix << QString(m_wrappedLineIndent, Space)
-                     << m_codeBlockFence << Newline;
-            m_fencedCodeBlock = false;
-            m_codeBlockFence.clear();
-        }
         m_wrappedLineIndent = 0;
         m_linePrefix.clear();
         if (blockFmt.hasProperty(QTextFormat::BlockQuoteLevel)) {

tests/auto/gui/text/qtextmarkdownwriter/data/listsAndCodeBlocks.md

@@ -0,0 +1,24 @@
+- something happens in the debugger like this:
+
+  ``` 
+  1   QQuickEventPoint::setGrabberItem                 qquickevents.cpp     869 0x7ffff7a963f2 
+  2   QQuickItem::grabMouse                            qquickitem.cpp      7599 0x7ffff7abea29 
+  3   QQuickWindowPrivate::deliverMatchingPointsToItem qquickwindow.cpp    2738 0x7ffff7aea34c 
+  4   QQuickWindowPrivate::deliverPressOrReleaseEvent  qquickwindow.cpp    2692 0x7ffff7ae9e57 
+  5   QQuickWindowPrivate::deliverMouseEvent           qquickwindow.cpp    1911 0x7ffff7ae561b 
+  6   QQuickWindowPrivate::deliverPointerEvent         qquickwindow.cpp    2454 0x7ffff7ae888c 
+  7   QQuickWindowPrivate::handleMouseEvent            qquickwindow.cpp    2282 0x7ffff7ae7f1a 
+  8   QQuickWindow::mousePressEvent                    qquickwindow.cpp    2249 0x7ffff7ae7bf5 
+  9   QQuickView::mousePressEvent                      qquickview.cpp       626 0x7ffff7bd6bad 
+  10  QWindow::event                                   qwindow.cpp         2258 0x7ffff70b2c54 
+  ```
+  and then I want to explain something about it.
+
+- something I tried to fix it:
+
+  ``` 
+  code goes here, probably c++
+  ```
+- still didn't fix it, expecting a breakthrough any day now
+- some sort of miracle
+- profit!

tests/auto/gui/text/qtextmarkdownwriter/tst_qtextmarkdownwriter.cpp

@@ -369,6 +369,7 @@ void tst_QTextMarkdownWriter::rewriteDocument_data()
     QTest::newRow("list items after headings") << "headingsAndLists.md";
     QTest::newRow("word wrap") << "wordWrap.md";
     QTest::newRow("links") << "links.md";
+    QTest::newRow("lists and code blocks") << "listsAndCodeBlocks.md";
 }
 
 void tst_QTextMarkdownWriter::rewriteDocument()