testlib: Don't print QCOMPARE values if they lack string representation

Before 0681a2dd5a8095baddb5905fb21a58ce19b958c5, QCOMPARE'ing types
for which no QTest::toString specialization exists did not output
Actual and Expected lines on failure, as that would only print <null>
for both values (which then look like the same value, confusingly).

Commit 0681a2dd5a8095baddb5905fb21a58ce19b958c5 changed that behavior,
and started printing the confusing <null> values.

Take care of the logic in the formatFailMessage function: if both values
are nullptr, then print only the variable names, but not the confusing
<null> text representation of the values.

Remove dead and duplicated code related to the formatting logic, add a
self-test function, and update the expected_cmptest files.

Fixes: QTBUG-104867
Pick-to: 6.4
Change-Id: I4be98e79f91196b14690a2cc0a68ffd50b431a45
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 0 insertions, 11 deletions

diff --git a/src/testlib/qtestcase.h b/src/testlib/qtestcase.h
index 7db64af8ab..0412f872f7 100644
--- a/src/testlib/qtestcase.h
+++ b/src/testlib/qtestcase.h
@@ -437,17 +437,6 @@ namespace QTest
     Q_TESTLIB_EXPORT QTestData &newRow(const char *dataTag);
     Q_TESTLIB_EXPORT QTestData &addRow(const char *format, ...) Q_ATTRIBUTE_FORMAT_PRINTF(1, 2);
 
-#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
-    // kept after adding implementation of <T1, T2> out of paranoia:
-    template <typename T>
-    inline bool qCompare(T const &t1, T const &t2, const char *actual, const char *expected,
-                        const char *file, int line)
-    {
-        return compare_helper(t1 == t2, "Compared values are not the same",
-                              toString(t1), toString(t2), actual, expected, file, line);
-    }
-#endif
-
     Q_TESTLIB_EXPORT bool qCompare(qfloat16 const &t1, qfloat16 const &t2,
                     const char *actual, const char *expected, const char *file, int line);