From 90e551d0a56987ebec1a5f8a89c11f3cea8ffe3c Mon Sep 17 00:00:00 2001
From: Thiago Macieira <thiago.macieira@intel.com>
Date: Thu, 12 Oct 2023 14:56:53 -0700
Subject: [PATCH] tst_QStorageInfo::{tempFile,caching}: try a to find a
 non-btrfs storage

These tests skip when we're writing to a btrfs filesystem because, for
some reason, the amount of free space does not update synchronously with
file writing. But instead of giving up if $TMPDIR is a btrfs, let's try
and use the $XDG_RUNTIME_DIR, which is usually a tmpfs.

This will work in the CI for the openSUSE set ups, where / is btrfs,
/tmp is not a separate tmpfs, but /run/user/1000 is available.

FAIL!  : tst_QStorageInfo::tempFile() The computed value is expected to be different from the baseline, but is not
   Computed (free)                : 25510780928
   Baseline (storage2.bytesFree()): 25510780928
   Loc: [tst_qstorageinfo.cpp(234)]

Change-Id: I8f3ce163ccc5408cac39fffd178d7af1c67ec988
Reviewed-by: Ahmad Samir <a.samirh78@gmail.com>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit ae03ffaffdcc8b2a0589b846e16ad016691dec29)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 .../io/qstorageinfo/tst_qstorageinfo.cpp      | 43 +++++++++++++++----
 1 file changed, 35 insertions(+), 8 deletions(-)

diff --git a/tests/auto/corelib/io/qstorageinfo/tst_qstorageinfo.cpp b/tests/auto/corelib/io/qstorageinfo/tst_qstorageinfo.cpp
index 94acef6bd47..c2edc5a7f04 100644
--- a/tests/auto/corelib/io/qstorageinfo/tst_qstorageinfo.cpp
+++ b/tests/auto/corelib/io/qstorageinfo/tst_qstorageinfo.cpp
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
 
 #include <QTest>
+#include <QStandardPaths>
 #include <QStorageInfo>
 #include <QTemporaryFile>
 
@@ -156,16 +157,44 @@ void tst_QStorageInfo::storageList()
     }
 }
 
+static bool checkFilesystemGoodForWriting(QTemporaryFile &file, QStorageInfo &storage)
+{
+#ifdef Q_OS_LINUX
+    auto reconstructAt = [](auto *where, auto &&... how) {
+        // it's very difficult to convince QTemporaryFile to change the path...
+        std::destroy_at(where);
+        q20::construct_at(where, std::forward<decltype(how)>(how)...);
+    };
+    if (storage.fileSystemType() == "btrfs") {
+        // let's see if we can find another, writable FS
+        QString runtimeDir = QStandardPaths::writableLocation(QStandardPaths::RuntimeLocation);
+        if (!runtimeDir.isEmpty()) {
+            reconstructAt(&file, runtimeDir + "/XXXXXX");
+            if (file.open()) {
+                storage.setPath(file.fileName());
+                if (storage.fileSystemType() != "btrfs")
+                    return true;
+            }
+        }
+        QTest::qSkip("btrfs does not synchronously update free space; this test would fail",
+                     __FILE__, __LINE__);
+        return false;
+    }
+#else
+    Q_UNUSED(file);
+    Q_UNUSED(storage);
+#endif
+    return true;
+}
+
 void tst_QStorageInfo::tempFile()
 {
     QTemporaryFile file;
     QVERIFY2(file.open(), qPrintable(file.errorString()));
 
     QStorageInfo storage1(file.fileName());
-#ifdef Q_OS_LINUX
-    if (storage1.fileSystemType() == "btrfs")
-        QSKIP("This test doesn't work on btrfs, probably due to a btrfs bug");
-#endif
+    if (!checkFilesystemGoodForWriting(file, storage1))
+        return;
 
     qint64 free = storage1.bytesFree();
     QCOMPARE_NE(free, -1);
@@ -188,10 +217,8 @@ void tst_QStorageInfo::caching()
     QVERIFY2(file.open(), qPrintable(file.errorString()));
 
     QStorageInfo storage1(file.fileName());
-#ifdef Q_OS_LINUX
-    if (storage1.fileSystemType() == "btrfs")
-        QSKIP("This test doesn't work on btrfs, probably due to a btrfs bug");
-#endif
+    if (!checkFilesystemGoodForWriting(file, storage1))
+        return;
 
     qint64 free = storage1.bytesFree();
     QStorageInfo storage2(storage1);