Restore Qt4.7 behaviour of QFileInfo::absolute(File)Path

Many applications relied on the undefined behaviour that the
filesystem engines returned clean paths (despite the documentation
stating that they may not), and consequently suffered regressions with
Qt 4.8.

Unix paths are once again cleaned if necessary.
Windows/Symbian paths were already cleaned, but now use the utility
function to check if a path is dirty, to avoid duplicated code.

Task-number: QTBUG-19995
Change-Id: If8c18469f149291c9d079ae3da23bc2087bbd49a
Reviewed-on: http://codereview.qt.nokia.com/4154
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Prasanth Ullattil <prasanth.ullattil@nokia.com>

4 files changed, 12 insertions, 10 deletions

diff --git a/src/corelib/io/qfilesystemengine_symbian.cpp b/src/corelib/io/qfilesystemengine_symbian.cpp
index 18c52cbb17..c8c1dfdc84 100644
--- a/src/corelib/io/qfilesystemengine_symbian.cpp
+++ b/src/corelib/io/qfilesystemengine_symbian.cpp
@@ -114,9 +114,7 @@ QFileSystemEntry QFileSystemEngine::absoluteName(const QFileSystemEntry &entry)
 {
     QString orig = entry.filePath();
     const bool isAbsolute = entry.isAbsolute();
-    const bool isDirty = (orig.contains(QLatin1String("/../")) || orig.contains(QLatin1String("/./")) ||
-            orig.contains(QLatin1String("//")) ||
-            orig.endsWith(QLatin1String("/..")) || orig.endsWith(QLatin1String("/.")));
+    const bool isDirty = !entry.isClean();
     if (isAbsolute && !isDirty)
         return entry;
 
diff --git a/src/corelib/io/qfilesystemengine_unix.cpp b/src/corelib/io/qfilesystemengine_unix.cpp
index f1e0758bbe..966daba021 100644
--- a/src/corelib/io/qfilesystemengine_unix.cpp
+++ b/src/corelib/io/qfilesystemengine_unix.cpp
@@ -218,7 +218,7 @@ QFileSystemEntry QFileSystemEngine::canonicalName(const QFileSystemEntry &entry,
 //static
 QFileSystemEntry QFileSystemEngine::absoluteName(const QFileSystemEntry &entry)
 {
-    if (entry.isAbsolute())
+    if (entry.isAbsolute() && entry.isClean())
         return entry;
 
     QByteArray orig = entry.nativeFilePath();
diff --git a/src/corelib/io/qfilesystemengine_win.cpp b/src/corelib/io/qfilesystemengine_win.cpp
index f704fc3e90..df34184091 100644
--- a/src/corelib/io/qfilesystemengine_win.cpp
+++ b/src/corelib/io/qfilesystemengine_win.cpp
@@ -508,11 +508,7 @@ QFileSystemEntry QFileSystemEngine::absoluteName(const QFileSystemEntry &entry)
 
     if (!entry.isRelative()) {
 #if !defined(Q_OS_WINCE)
-        if (entry.isAbsolute()
-            && !entry.filePath().contains(QLatin1String("/../"))
-            && !entry.filePath().contains(QLatin1String("/./"))
-            && !entry.filePath().endsWith(QLatin1String("/.."))
-            && !entry.filePath().endsWith(QLatin1String("/."))) {
+        if (entry.isAbsolute() && entry.isClean()) {
             ret = entry.filePath();
         }  else {
             ret = QDir::fromNativeSeparators(nativeAbsoluteFilePath(entry.filePath()));
diff --git a/tests/auto/qfileinfo/tst_qfileinfo.cpp b/tests/auto/qfileinfo/tst_qfileinfo.cpp
index 92046d3e12..878493b8e3 100644
--- a/tests/auto/qfileinfo/tst_qfileinfo.cpp
+++ b/tests/auto/qfileinfo/tst_qfileinfo.cpp
@@ -481,6 +481,11 @@ void tst_QFileInfo::absolutePath_data()
     QTest::newRow("c:\\autoexec.bat") << "c:\\autoexec.bat" << "C:/"
                                       << "autoexec.bat";
 #endif
+    QTest::newRow("QTBUG-19995.1") << drivePrefix + "/System/Library/StartupItems/../Frameworks"
+                                   << drivePrefix + "/System/Library"
+                                   << "Frameworks";
+    QTest::newRow("QTBUG-19995.2") << drivePrefix + "/System/Library/StartupItems/../Frameworks/"
+                                   << drivePrefix + "/System/Library/Frameworks" << "";
 }
 
 void tst_QFileInfo::absolutePath()
@@ -502,6 +507,7 @@ void tst_QFileInfo::absFilePath_data()
 
     QTest::newRow("relativeFile") << "tmp.txt" << QDir::currentPath() + "/tmp.txt";
     QTest::newRow("relativeFileInSubDir") << "temp/tmp.txt" << QDir::currentPath() + "/" + "temp/tmp.txt";
+    QString drivePrefix;
 #if (defined(Q_OS_WIN) && !defined(Q_OS_WINCE)) || defined(Q_OS_SYMBIAN)
     QString curr = QDir::currentPath();
 
@@ -510,7 +516,7 @@ void tst_QFileInfo::absFilePath_data()
     QTest::newRow("absFilePath") << "c:\\home\\andy\\tmp.txt" << "C:/home/andy/tmp.txt";
 
     // Make sure drive-relative paths return correct absolute paths (task 255326)
-    QString drivePrefix = QDir::currentPath().left(2);
+    drivePrefix = QDir::currentPath().left(2);
     QString nonCurrentDrivePrefix =
         drivePrefix.left(1).compare("X", Qt::CaseInsensitive) == 0 ? QString("Y:") : QString("X:");
 
@@ -520,6 +526,8 @@ void tst_QFileInfo::absFilePath_data()
 #else
     QTest::newRow("absFilePath") << "/home/andy/tmp.txt" << "/home/andy/tmp.txt";
 #endif
+    QTest::newRow("QTBUG-19995") << drivePrefix + "/System/Library/StartupItems/../Frameworks"
+                                 << drivePrefix + "/System/Library/Frameworks";
 }
 
 void tst_QFileInfo::absFilePath()