QFileInfo: harmonize QFileInfo() and QFileInfo("")

If a QFileInfo was constructed with an empty path, which could happen
with QFileInfo(QFile()) or via QDir, etc., then it would issue system
calls to empty paths and could even produce warnings. This commit makes
am empty path name be the same as a default-constructed QFileInfo and
corrects the use if 0 for ownerId and groupId to match the
documentation.

[ChangeLog][Important Behavior Changes] QFileInfo on empty strings now
behaves like the default-constructed QFileInfo. Notably, path() will now
be the empty string too, instead of ".", which means absoluteFilePath()
is no longer the current working directory.

Change-Id: I8d96dea9955d4c749b99fffd14ce34968b1d9bbf
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 81 insertions, 48 deletions

diff --git a/tests/auto/corelib/io/qfileinfo/tst_qfileinfo.cpp b/tests/auto/corelib/io/qfileinfo/tst_qfileinfo.cpp
index 94273e2394..3fa765e2fa 100644
--- a/tests/auto/corelib/io/qfileinfo/tst_qfileinfo.cpp
+++ b/tests/auto/corelib/io/qfileinfo/tst_qfileinfo.cpp
@@ -232,8 +232,9 @@ private slots:
 #endif
     void group();
 
+    void invalidState_data();
     void invalidState();
-    void nonExistingFileDates();
+    void nonExistingFile();
 
 private:
     const QString m_currentDir;
@@ -1366,7 +1367,7 @@ void tst_QFileInfo::isNativePath_data()
     QTest::addColumn<bool>("isNativePath");
 
     QTest::newRow("default-constructed") << QString() << false;
-    QTest::newRow("empty") << QString("") << true;
+    QTest::newRow("empty") << QString("") << false;
 
     QTest::newRow("local root") << QString::fromLatin1("/") << true;
     QTest::newRow("local non-existent file") << QString::fromLatin1("/abrakadabra.boo") << true;
@@ -1896,64 +1897,96 @@ void tst_QFileInfo::group()
     QCOMPARE(fi.group(), expected);
 }
 
-void tst_QFileInfo::invalidState()
+static void stateCheck(const QFileInfo &info, const QString &dirname, const QString &filename)
 {
-    // Shouldn't crash;
-
-    {
-        QFileInfo info;
-        QCOMPARE(info.size(), qint64(0));
-        QVERIFY(!info.exists());
-
-        info.setCaching(false);
+    QCOMPARE(info.size(), qint64(0));
+    QVERIFY(!info.exists());
 
-        info.created();
-        info.birthTime();
-        info.metadataChangeTime();
-        info.lastRead();
-        info.lastModified();
+    QString path;
+    QString abspath;
+    if (!dirname.isEmpty()) {
+        path = ".";
+        abspath = dirname + '/' + filename;
     }
 
-    {
-        QFileInfo info("");
-        QCOMPARE(info.size(), qint64(0));
-        QVERIFY(!info.exists());
-
-        info.setCaching(false);
+    QCOMPARE(info.filePath(), filename);
+    QCOMPARE(info.absoluteFilePath(), abspath);
+    QCOMPARE(info.canonicalFilePath(), QString());
+    QCOMPARE(info.fileName(), filename);
+    QCOMPARE(info.baseName(), filename);
+    QCOMPARE(info.completeBaseName(), filename);
+    QCOMPARE(info.suffix(), QString());
+    QCOMPARE(info.bundleName(), QString());
+    QCOMPARE(info.completeSuffix(), QString());
+
+    QVERIFY(info.isRelative());
+    QCOMPARE(info.path(), path);
+    QCOMPARE(info.absolutePath(), dirname);
+    QCOMPARE(info.dir().path(), ".");
+
+    // these don't look right
+    QCOMPARE(info.canonicalPath(), path);
+    QCOMPARE(info.absoluteDir().path(), dirname.isEmpty() ? "." : dirname);
+
+    QVERIFY(!info.isReadable());
+    QVERIFY(!info.isWritable());
+    QVERIFY(!info.isExecutable());
+    QVERIFY(!info.isHidden());
+    QVERIFY(!info.isFile());
+    QVERIFY(!info.isDir());
+    QVERIFY(!info.isSymLink());
+    QVERIFY(!info.isBundle());
+    QVERIFY(!info.isRoot());
+    QCOMPARE(info.isNativePath(), !filename.isEmpty());
+
+    QCOMPARE(info.readLink(), QString());
+    QCOMPARE(info.ownerId(), uint(-2));
+    QCOMPARE(info.groupId(), uint(-2));
+    QCOMPARE(info.owner(), QString());
+    QCOMPARE(info.group(), QString());
+
+    QCOMPARE(info.permissions(), QFile::Permissions());
 
-        info.created();
-        info.birthTime();
-        info.metadataChangeTime();
-        info.lastRead();
-        info.lastModified();
-    }
+    QVERIFY(!info.created().isValid());
+    QVERIFY(!info.birthTime().isValid());
+    QVERIFY(!info.metadataChangeTime().isValid());
+    QVERIFY(!info.lastRead().isValid());
+    QVERIFY(!info.lastModified().isValid());
+};
 
-    {
-        QFileInfo info("file-doesn't-really-exist.txt");
-        QCOMPARE(info.size(), qint64(0));
-        QVERIFY(!info.exists());
+void tst_QFileInfo::invalidState_data()
+{
+    QTest::addColumn<int>("mode");
+    QTest::newRow("default") << 0;
+    QTest::newRow("empty") << 1;
+    QTest::newRow("copy-of-default") << 2;
+    QTest::newRow("copy-of-empty") << 3;
+}
 
-        info.setCaching(false);
+void tst_QFileInfo::invalidState()
+{
+    // Shouldn't crash or produce warnings
+    QFETCH(int, mode);
+    const QFileInfo &info = (mode & 1 ? QFileInfo("") : QFileInfo());
 
-        info.created();
-        info.birthTime();
-        info.metadataChangeTime();
-        info.lastRead();
-        info.lastModified();
+    if (mode & 2) {
+        QFileInfo copy(info);
+        stateCheck(copy, QString(), QString());
+    } else {
+        stateCheck(info, QString(), QString());
     }
-
-    QVERIFY(true);
 }
 
-void tst_QFileInfo::nonExistingFileDates()
+void tst_QFileInfo::nonExistingFile()
 {
-    QFileInfo info("non-existing-file.foobar");
-    QVERIFY(!info.exists());
-    QVERIFY(!info.created().isValid());
-    QVERIFY(!info.birthTime().isValid());
-    QVERIFY(!info.metadataChangeTime().isValid());
-    QVERIFY(!info.lastRead().isValid());
-    QVERIFY(!info.lastModified().isValid());
+    QString dirname = QDir::currentPath();
+    QString cdirname = QFileInfo(dirname).canonicalFilePath();
+    if (dirname != cdirname)
+        QDir::setCurrent(cdirname); // chdir() to our canonical path
+
+    QString filename = "non-existing-file-foobar";
+    QFileInfo info(filename);
+    stateCheck(info, dirname, filename);
 }
 
 QTEST_MAIN(tst_QFileInfo)