Merge fixes for QDir::operator==

There were two fixes in 4.8 which each fixed a part of the problem.
Comparing canonical paths is more correct, but is only possible where
both directories exist. If neither directory exists, then compare
absolute paths instead.
Changed a regression test, because /tmp is a symbolic link on MacOS.
I.E. "/tmp/.." is canonically "/private" and not "/" as expected.

Task-Number: QTBUG-20495
Reviewed-By: joao
(cherry-picked from ad35d25e78c8252a72108a4ba931934047c4707e)

Change-Id: Ia4986e8337f0e512e1a3398a5a4dd36e62680b9c
Reviewed-on: http://codereview.qt-project.org/5813
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Shane Kearns <shane.kearns@accenture.com>

1 files changed, 17 insertions, 2 deletions

diff --git a/src/corelib/io/qdir.cpp b/src/corelib/io/qdir.cpp
index 0c7050095d..68f015ff53 100644
--- a/src/corelib/io/qdir.cpp
+++ b/src/corelib/io/qdir.cpp
@@ -1600,8 +1600,23 @@ bool QDir::operator==(const QDir &dir) const
        && d->sort == other->sort
        && d->nameFilters == other->nameFilters) {
 
-        // Fallback to expensive canonical path computation
-        return canonicalPath().compare(dir.canonicalPath(), sensitive) == 0;
+        // Assume directories are the same if path is the same
+        if (d->dirEntry.filePath() == other->dirEntry.filePath())
+            return true;
+
+        if (exists()) {
+            if (!dir.exists())
+                return false; //can't be equal if only one exists
+            // Both exist, fallback to expensive canonical path computation
+            return canonicalPath().compare(dir.canonicalPath(), sensitive) == 0;
+        } else {
+            if (dir.exists())
+                return false; //can't be equal if only one exists
+            // Neither exists, compare absolute paths rather than canonical (which would be empty strings)
+            d->resolveAbsoluteEntry();
+            other->resolveAbsoluteEntry();
+            return d->absoluteDirEntry.filePath().compare(other->absoluteDirEntry.filePath(), sensitive) == 0;
+        }
     }
     return false;
 }