Make QDir::relativeFilePath() return "." for a path to itself.

The rationale being that the empty string is not a valid path component.

[ChangeLog][QtCore][QDir] QDir::relativeFilePath() now returns "."
instead of an empty string if the given path is the same as the
directory.

Change-Id: Ibcf31904b2ae5edf5639d4c2e5ba234365d347fd
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>

3 files changed, 11 insertions, 6 deletions

diff --git a/src/corelib/io/qdir.cpp b/src/corelib/io/qdir.cpp
index 9b1ec3917a..6687ff846c 100644
--- a/src/corelib/io/qdir.cpp
+++ b/src/corelib/io/qdir.cpp
@@ -777,6 +777,8 @@ QString QDir::relativeFilePath(const QString &fileName) const
             result += QLatin1Char('/');
     }
 
+    if (result.isEmpty())
+        return QLatin1String(".");
     return result;
 }
 
diff --git a/tests/auto/corelib/io/qdir/tst_qdir.cpp b/tests/auto/corelib/io/qdir/tst_qdir.cpp
index e8a7105f6e..45289df398 100644
--- a/tests/auto/corelib/io/qdir/tst_qdir.cpp
+++ b/tests/auto/corelib/io/qdir/tst_qdir.cpp
@@ -1366,6 +1366,9 @@ void tst_QDir::relativeFilePath_data()
 
     QTest::newRow("11") << "" << "" << "";
 
+    QTest::newRow("same path 1") << "/tmp" << "/tmp" << ".";
+    QTest::newRow("same path 2") << "//tmp" << "/tmp/" << ".";
+
 #if (defined(Q_OS_WIN) && !defined(Q_OS_WINCE))
     QTest::newRow("12") << "C:/foo/bar" << "ding" << "ding";
     QTest::newRow("13") << "C:/foo/bar" << "C:/ding/dong" << "../../ding/dong";
@@ -1373,10 +1376,10 @@ void tst_QDir::relativeFilePath_data()
     QTest::newRow("15") << "C:/foo/bar" << "D:/ding/dong" << "D:/ding/dong";
     QTest::newRow("16") << "C:" << "C:/ding/dong" << "ding/dong";
     QTest::newRow("17") << "C:/" << "C:/ding/dong" << "ding/dong";
-    QTest::newRow("18") << "C:" << "C:" << "";
-    QTest::newRow("19") << "C:/" << "C:" << "";
-    QTest::newRow("20") << "C:" << "C:/" << "";
-    QTest::newRow("21") << "C:/" << "C:/" << "";
+    QTest::newRow("18") << "C:" << "C:" << ".";
+    QTest::newRow("19") << "C:/" << "C:" << ".";
+    QTest::newRow("20") << "C:" << "C:/" << ".";
+    QTest::newRow("21") << "C:/" << "C:/" << ".";
     QTest::newRow("22") << "C:" << "C:file.txt" << "file.txt";
     QTest::newRow("23") << "C:/" << "C:file.txt" << "file.txt";
     QTest::newRow("24") << "C:" << "C:/file.txt" << "file.txt";
diff --git a/tests/auto/tools/qmakelib/evaltest.cpp b/tests/auto/tools/qmakelib/evaltest.cpp
index fab2cdce17..bed4c792a1 100644
--- a/tests/auto/tools/qmakelib/evaltest.cpp
+++ b/tests/auto/tools/qmakelib/evaltest.cpp
@@ -1356,7 +1356,7 @@ void tst_qmakelib::addReplaceFunctions(const QString &qindir)
 
     QTest::newRow("$$relative_path(): relative file to empty")
             << "VAR = $$relative_path(dir/..)"
-            << "VAR ="
+            << "VAR = ."
             << ""
             << true;
 
@@ -1368,7 +1368,7 @@ void tst_qmakelib::addReplaceFunctions(const QString &qindir)
 
     QTest::newRow("$$relative_path(): empty file & path")
             << "VAR = $$relative_path('', /root/sub)"
-            << "VAR ="
+            << "VAR = ."
             << ""
             << true;