QMimeDatabase: fix handling of conflicting globs

This code always intended to follow the recommended checking order from
the spec, which says "if multiple globs match, use file contents".
But if the globs had different weights, it would discard globs with
lower weights, and then wrongly conclude, if there is only one glob
left, that there was no ambiguity.

The correct way is rather: remember that multiple globs matched,
do determination from contents, and if that didn't work, *then* use
(one of) the highest-weight glob(s).

This fixes PGP-encrypted *.asc files being detected as text/plain rather
than application/pgp-encrypted.
(https://bugs.kde.org/show_bug.cgi?id=346754)

Change-Id: I734459daf9f502baa95ebb89432819964e0ce304
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 6 insertions, 9 deletions

diff --git a/src/corelib/mimetypes/qmimeprovider.cpp b/src/corelib/mimetypes/qmimeprovider.cpp
index 65b011b439..959421bf52 100644
--- a/src/corelib/mimetypes/qmimeprovider.cpp
+++ b/src/corelib/mimetypes/qmimeprovider.cpp
@@ -287,13 +287,13 @@ QMimeType QMimeBinaryProvider::mimeTypeForName(const QString &name)
     return mimeTypeForNameUnchecked(name);
 }
 
-QStringList QMimeBinaryProvider::findByFileName(const QString &fileName, QString *foundSuffix)
+QMimeGlobMatchResult QMimeBinaryProvider::findByFileName(const QString &fileName)
 {
     checkCache();
+    QMimeGlobMatchResult result;
     if (fileName.isEmpty())
-        return QStringList();
+        return result;
     const QString lowerFileName = fileName.toLower();
-    QMimeGlobMatchResult result;
     // TODO this parses in the order (local, global). Check that it handles "NOGLOBS" correctly.
     for (CacheFile *cacheFile : qAsConst(m_cacheFiles)) {
         matchGlobList(result, cacheFile, cacheFile->getUint32(PosLiteralListOffset), fileName);
@@ -305,9 +305,7 @@ QStringList QMimeBinaryProvider::findByFileName(const QString &fileName, QString
         if (result.m_matchingMimeTypes.isEmpty())
             matchSuffixTree(result, cacheFile, numRoots, firstRootOffset, fileName, fileName.length() - 1, true);
     }
-    if (foundSuffix)
-        *foundSuffix = result.m_foundSuffix;
-    return result.m_matchingMimeTypes;
+    return result;
 }
 
 void QMimeBinaryProvider::matchGlobList(QMimeGlobMatchResult &result, CacheFile *cacheFile, int off, const QString &fileName)
@@ -728,12 +726,11 @@ QMimeType QMimeXMLProvider::mimeTypeForName(const QString &name)
     return m_nameMimeTypeMap.value(name);
 }
 
-QStringList QMimeXMLProvider::findByFileName(const QString &fileName, QString *foundSuffix)
+QMimeGlobMatchResult QMimeXMLProvider::findByFileName(const QString &fileName)
 {
     ensureLoaded();
 
-    const QStringList matchingMimeTypes = m_mimeTypeGlobs.matchingGlobs(fileName, foundSuffix);
-    return matchingMimeTypes;
+    return m_mimeTypeGlobs.matchingGlobs(fileName);
 }
 
 QMimeType QMimeXMLProvider::findByMagic(const QByteArray &data, int *accuracyPtr)