Support markdown in QTextEditMimeData; fix pasting trailing newlines

- Since 4edcea762d9ce334c4c1a78234c90c118b81da87 the dropsite example
  shows markdown if available; and now it shows that when we do DnD
  of a selection from the richtext example, text/markdown is available.
- If we artificially make html unavailable, copying and pasting between
  widget-based rich text editors uses markdown.

In case markdown writer output contains unnecessary backticks due to
monospace fonts getting used, the workaround from
1ad456c908467212bc30223a69eb7524b64b86e1 is applied.

Pick-to: 6.4
Task-number: QTBUG-76105
Task-number: QTBUG-103484
Change-Id: Ie6ca4dbb450dbc36b3d09fd0df1ae5909aaebca7
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

1 files changed, 11 insertions, 0 deletions

diff --git a/tests/auto/corelib/kernel/qmimedata/tst_qmimedata.cpp b/tests/auto/corelib/kernel/qmimedata/tst_qmimedata.cpp
index 16d5c5308e..03b07c41ec 100644
--- a/tests/auto/corelib/kernel/qmimedata/tst_qmimedata.cpp
+++ b/tests/auto/corelib/kernel/qmimedata/tst_qmimedata.cpp
@@ -72,12 +72,19 @@ void tst_QMimeData::data() const
     mimeData.setData("text/plain", "pirates");
     QCOMPARE(mimeData.data("text/plain"), QByteArray("pirates"));
     QCOMPARE(mimeData.data("text/html").length(), 0);
+    QCOMPARE(mimeData.data("text/markdown").length(), 0);
 
     // html time
     mimeData.setData("text/html", "ninjas");
     QCOMPARE(mimeData.data("text/html"), QByteArray("ninjas"));
     QCOMPARE(mimeData.data("text/plain"), QByteArray("pirates")); // make sure text not damaged
     QCOMPARE(mimeData.data("text/html"), mimeData.html().toLatin1());
+
+    // markdown time
+    mimeData.setData("text/markdown", "vikings");
+    QCOMPARE(mimeData.data("text/markdown"), QByteArray("vikings"));
+    QCOMPARE(mimeData.data("text/html"), QByteArray("ninjas"));
+    QCOMPARE(mimeData.data("text/plain"), QByteArray("pirates"));
 }
 
 void tst_QMimeData::formats() const
@@ -92,6 +99,10 @@ void tst_QMimeData::formats() const
     mimeData.setData("text/html", "ninjas");
     QCOMPARE(mimeData.formats(), QStringList() << "text/plain" << "text/html");
 
+    // set markdown, verify
+    mimeData.setData("text/markdown", "vikings");
+    QCOMPARE(mimeData.formats(), QStringList() << "text/plain" << "text/html" << "text/markdown");
+
     // clear, verify
     mimeData.clear();
     QCOMPARE(mimeData.formats(), QStringList());