QFileSystemWatcher/Win: remove the pre-QFileInfo path normalization

It's completely unnecessary, since QFileInfo will query the file system
anyway and that has a much better view of what is normalized and what
isn't. More importantly, this fixes the mistake in failing to normalize
properly in removePaths(), which removed the ending slash of a root
directory such as "C:\\". That caused the path to become "C:", which
QFileInfo interprets as "current path on drive C:".

[ChangeLog][QtCore][QFileSystemWatcher] Fixed a bug that prevented
removePaths() from removing the root of a drive on Windows.

Fixes: QTBUG-110986
Pick-to: 5.15 6.2 6.4 6.5
Change-Id: I9671dee8ceb64aa9b9cafffd17419b6d69670876
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

2 files changed, 20 insertions, 14 deletions

diff --git a/src/corelib/io/qfilesystemwatcher_win.cpp b/src/corelib/io/qfilesystemwatcher_win.cpp
index 7586054c27..a0b2b006d6 100644
--- a/src/corelib/io/qfilesystemwatcher_win.cpp
+++ b/src/corelib/io/qfilesystemwatcher_win.cpp
@@ -332,12 +332,7 @@ QStringList QWindowsFileSystemWatcherEngine::addPaths(const QStringList &paths,
     QStringList unhandled;
     for (const QString &path : paths) {
         auto sg = qScopeGuard([&] { unhandled.push_back(path); });
-        QString normalPath = path;
-        if ((normalPath.endsWith(u'/') && !normalPath.endsWith(":/"_L1))
-            || (normalPath.endsWith(u'\\') && !normalPath.endsWith(":\\"_L1))) {
-            normalPath.chop(1);
-        }
-        QFileInfo fileInfo(normalPath);
+        QFileInfo fileInfo(path);
         fileInfo.stat();
         if (!fileInfo.exists())
             continue;
@@ -351,7 +346,7 @@ QStringList QWindowsFileSystemWatcherEngine::addPaths(const QStringList &paths,
                 continue;
         }
 
-        DEBUG() << "Looking for a thread/handle for" << normalPath;
+        DEBUG() << "Looking for a thread/handle for" << fileInfo.path();
 
         const QString absolutePath = isDir ? fileInfo.absoluteFilePath() : fileInfo.absolutePath();
         const uint flags = isDir
@@ -495,11 +490,8 @@ QStringList QWindowsFileSystemWatcherEngine::removePaths(const QStringList &path
     QStringList unhandled;
     for (const QString &path : paths) {
         auto sg = qScopeGuard([&] { unhandled.push_back(path); });
-        QString normalPath = path;
-        if (normalPath.endsWith(u'/') || normalPath.endsWith(u'\\'))
-            normalPath.chop(1);
-        QFileInfo fileInfo(normalPath);
-        DEBUG() << "removing" << normalPath;
+        QFileInfo fileInfo(path);
+        DEBUG() << "removing" << fileInfo.path();
         QString absolutePath = fileInfo.absoluteFilePath();
         QList<QWindowsFileSystemWatcherEngineThread *>::iterator jt, end;
         end = threads.end();
diff --git a/tests/auto/corelib/io/qfilesystemwatcher/tst_qfilesystemwatcher.cpp b/tests/auto/corelib/io/qfilesystemwatcher/tst_qfilesystemwatcher.cpp
index 5acab6e473..dfdf4e05c1 100644
--- a/tests/auto/corelib/io/qfilesystemwatcher/tst_qfilesystemwatcher.cpp
+++ b/tests/auto/corelib/io/qfilesystemwatcher/tst_qfilesystemwatcher.cpp
@@ -396,8 +396,14 @@ void tst_QFileSystemWatcher::addPaths()
     QFileSystemWatcher watcher;
     QStringList paths;
     paths << QDir::homePath() << QDir::tempPath();
+#ifndef Q_OS_QNX
+    // Adding this makes QNX fail and we haven't investigated why
+    for (const QFileInfo &fi : QDir::drives())
+        paths << fi.absoluteFilePath();     // on Unix, this will be just "/"
+#endif
+
     QCOMPARE(watcher.addPaths(paths), QStringList());
-    QCOMPARE(watcher.directories().size(), 2);
+    QCOMPARE(watcher.directories().size(), paths.size());
 
     // With empty list
     paths.clear();
@@ -464,8 +470,14 @@ void tst_QFileSystemWatcher::removePaths()
     QFileSystemWatcher watcher;
     QStringList paths;
     paths << QDir::homePath() << QDir::tempPath();
+#ifndef Q_OS_QNX
+    // Adding this makes QNX fail and we haven't investigated why
+    for (const QFileInfo &fi : QDir::drives())
+        paths << fi.absoluteFilePath();     // on Unix, this will be just "/"
+#endif
+
     QCOMPARE(watcher.addPaths(paths), QStringList());
-    QCOMPARE(watcher.directories().size(), 2);
+    QCOMPARE(watcher.directories().size(), paths.size());
     QCOMPARE(watcher.removePaths(paths), QStringList());
     QCOMPARE(watcher.directories().size(), 0);
 
@@ -613,9 +625,11 @@ void tst_QFileSystemWatcher::nonExistingFile()
                               QStringList() << "../..//./does-not-exist");
 
     // empty path is not actually a failure
+    QTest::ignoreMessage(QtWarningMsg, "QFileSystemWatcher::addPaths: list is empty");
     QCOMPARE(watcher.addPaths(QStringList() << QString()), QStringList());
 
     // empty path is not actually a failure
+    QTest::ignoreMessage(QtWarningMsg, "QFileSystemWatcher::removePaths: list is empty");
     QCOMPARE(watcher.removePaths(QStringList() << QString()), QStringList());
 }