qt: Use temporary .part file names when creating archives

* lang/qt/src/util.h, lang/qt/src/util.cpp (class PartialFileGuard):
New.
* lang/qt/src/util.cpp (getRandomCharacters, createPartFileName): New.
* lang/qt/src/qgpgmeencryptarchivejob.cpp (encrypt_to_filename): Use
PartialFileGuard.
* lang/qt/src/qgpgmesignarchivejob.cpp (sign_to_filename): Ditto.
* lang/qt/src/qgpgmesignencryptarchivejob.cpp
(sign_encrypt_to_filename): Ditto.
--

When creating signed and/or encrypted archives, gpgtar now writes the
result to a temporary file name. On success, the archive is renamed to
the final file name. Otherwise, the (partially written) temporary file
is removed (if possible).

GnuPG-bug-id: 6721

1 files changed, 22 insertions, 0 deletions

diff --git a/lang/qt/src/util.h b/lang/qt/src/util.h
index 9128e4bf..c2d63405 100644
--- a/lang/qt/src/util.h
+++ b/lang/qt/src/util.h
@@ -57,4 +57,26 @@ QStringList toFingerprints(const std::vector<GpgME::Key> &keys);
 
 void removeFile(const QString &fileName);
 
+/**
+ * Helper for using a temporary "part" file for writing a result to, similar
+ * to what browsers do when downloading files.
+ * On success, you commit() which renames the temporary file to the
+ * final file name. Otherwise, you do nothing and let the helper remove the
+ * temporary file on destruction.
+ */
+class PartialFileGuard
+{
+public:
+    explicit PartialFileGuard(const QString &fileName);
+    ~PartialFileGuard();
+
+    QString tempFileName() const;
+
+    bool commit();
+
+private:
+    QString mFileName;
+    QString mTempFileName;
+};
+
 #endif // __QGPGME_UTIL_H__