From e1ca08580c5b287b925f5eb919fd2d6d617ef2b0 Mon Sep 17 00:00:00 2001
From: David Faure <david.faure@kdab.com>
Date: Mon, 28 Aug 2023 17:42:02 +0200
Subject: [PATCH 120/147] QMimeDatabase: fix detection of pattern conflict in
 different prefixes

Installing a second mimetype with *.txt as glob had a different
effect depending on whether it was installed into the same prefix
or a different prefix as the one where text/plain is installed.

Pick-to: 6.6
Change-Id: I7f54b8efe22f620eb57257745c48fe5402c87626
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(based on commit 1b39e61a775d70ee96287e9f0e418cb5741e6638)
---
 src/corelib/mimetypes/qmimeprovider.cpp       | 23 ++++++++++++-------
 src/corelib/mimetypes/qmimeprovider_p.h       |  2 +-
 .../mimetypes/qmimedatabase/testdata.qrc      |  1 +
 .../qmimedatabase/text-plain-subclass.xml     | 15 ++++++++++++
 .../qmimedatabase/tst_qmimedatabase.cpp       |  3 +++
 5 files changed, 35 insertions(+), 9 deletions(-)
 create mode 100644 tests/auto/corelib/mimetypes/qmimedatabase/text-plain-subclass.xml

diff --git a/src/corelib/mimetypes/qmimeprovider.cpp b/src/corelib/mimetypes/qmimeprovider.cpp
index 4642d0f2d0..5125704cf1 100644
--- a/src/corelib/mimetypes/qmimeprovider.cpp
+++ b/src/corelib/mimetypes/qmimeprovider.cpp
@@ -242,24 +242,28 @@ void QMimeBinaryProvider::addFileNameMatches(const QString &fileName, QMimeGlobM
         return;
     Q_ASSERT(m_cacheFile);
     const QString lowerFileName = fileName.toLower();
+    int numMatches = 0;
     // Check literals (e.g. "Makefile")
-    matchGlobList(result, m_cacheFile, m_cacheFile->getUint32(PosLiteralListOffset), fileName);
+    numMatches = matchGlobList(result, m_cacheFile, m_cacheFile->getUint32(PosLiteralListOffset), fileName);
     // Check the very common *.txt cases with the suffix tree
-    if (result.m_matchingMimeTypes.isEmpty()) {
+    if (numMatches == 0) {
         const int reverseSuffixTreeOffset = m_cacheFile->getUint32(PosReverseSuffixTreeOffset);
         const int numRoots = m_cacheFile->getUint32(reverseSuffixTreeOffset);
         const int firstRootOffset = m_cacheFile->getUint32(reverseSuffixTreeOffset + 4);
-        matchSuffixTree(result, m_cacheFile, numRoots, firstRootOffset, lowerFileName, lowerFileName.length() - 1, false);
-        if (result.m_matchingMimeTypes.isEmpty())
-            matchSuffixTree(result, m_cacheFile, numRoots, firstRootOffset, fileName, fileName.length() - 1, true);
+        if (matchSuffixTree(result, m_cacheFile, numRoots, firstRootOffset, lowerFileName, lowerFileName.length() - 1, false)) {
+            ++numMatches;
+        } else if (matchSuffixTree(result, m_cacheFile, numRoots, firstRootOffset, fileName, fileName.length() - 1, true)) {
+            ++numMatches;
+        }
     }
     // Check complex globs (e.g. "callgrind.out[0-9]*" or "README*")
-    if (result.m_matchingMimeTypes.isEmpty())
+    if (numMatches == 0)
         matchGlobList(result, m_cacheFile, m_cacheFile->getUint32(PosGlobListOffset), fileName);
 }
 
-void QMimeBinaryProvider::matchGlobList(QMimeGlobMatchResult &result, CacheFile *cacheFile, int off, const QString &fileName)
+int QMimeBinaryProvider::matchGlobList(QMimeGlobMatchResult &result, CacheFile *cacheFile, int off, const QString &fileName)
 {
+    int numMatches = 0;
     const int numGlobs = cacheFile->getUint32(off);
     //qDebug() << "Loading" << numGlobs << "globs from" << cacheFile->file.fileName() << "at offset" << cacheFile->globListOffset;
     for (int i = 0; i < numGlobs; ++i) {
@@ -275,9 +279,12 @@ void QMimeBinaryProvider::matchGlobList(QMimeGlobMatchResult &result, CacheFile
         //qDebug() << pattern << mimeType << weight << caseSensitive;
         QMimeGlobPattern glob(pattern, QString() /*unused*/, weight, qtCaseSensitive);
 
-        if (glob.matchFileName(fileName))
+        if (glob.matchFileName(fileName)) {
             result.addMatch(QLatin1String(mimeType), weight, pattern);
+            ++numMatches;
+        }
     }
+    return numMatches;
 }
 
 bool QMimeBinaryProvider::matchSuffixTree(QMimeGlobMatchResult &result, QMimeBinaryProvider::CacheFile *cacheFile, int numEntries, int firstOffset, const QString &fileName, int charPos, bool caseSensitiveCheck)
diff --git a/src/corelib/mimetypes/qmimeprovider_p.h b/src/corelib/mimetypes/qmimeprovider_p.h
index f9c8ef384c..5b328a7d5e 100644
--- a/src/corelib/mimetypes/qmimeprovider_p.h
+++ b/src/corelib/mimetypes/qmimeprovider_p.h
@@ -115,7 +115,7 @@ public:
 private:
     struct CacheFile;
 
-    void matchGlobList(QMimeGlobMatchResult &result, CacheFile *cacheFile, int offset, const QString &fileName);
+    int matchGlobList(QMimeGlobMatchResult &result, CacheFile *cacheFile, int offset, const QString &fileName);
     bool matchSuffixTree(QMimeGlobMatchResult &result, CacheFile *cacheFile, int numEntries, int firstOffset, const QString &fileName, int charPos, bool caseSensitiveCheck);
     bool matchMagicRule(CacheFile *cacheFile, int numMatchlets, int firstOffset, const QByteArray &data);
     QLatin1String iconForMime(CacheFile *cacheFile, int posListOffset, const QByteArray &inputMime);
diff --git a/tests/auto/corelib/mimetypes/qmimedatabase/testdata.qrc b/tests/auto/corelib/mimetypes/qmimedatabase/testdata.qrc
index 1002d0195d..d5774a0213 100644
--- a/tests/auto/corelib/mimetypes/qmimedatabase/testdata.qrc
+++ b/tests/auto/corelib/mimetypes/qmimedatabase/testdata.qrc
@@ -3,6 +3,7 @@
         <file alias="yast2-metapackage-handler-mimetypes.xml">yast2-metapackage-handler-mimetypes.xml</file>
         <file alias="qml-again.xml">qml-again.xml</file>
         <file alias="text-x-objcsrc.xml">text-x-objcsrc.xml</file>
+        <file alias="text-plain-subclass.xml">text-plain-subclass.xml</file>
         <file alias="test.qml">test.qml</file>
         <file>invalid-magic1.xml</file>
         <file>invalid-magic2.xml</file>
diff --git a/tests/auto/corelib/mimetypes/qmimedatabase/text-plain-subclass.xml b/tests/auto/corelib/mimetypes/qmimedatabase/text-plain-subclass.xml
new file mode 100644
index 0000000000..7b5cb7506d
--- /dev/null
+++ b/tests/auto/corelib/mimetypes/qmimedatabase/text-plain-subclass.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<mime-info xmlns='http://www.freedesktop.org/standards/shared-mime-info'>
+    <mime-type type="text/x-microdvd">
+        <comment>MicroDVD subtitles</comment>
+        <sub-class-of type="text/plain"/>
+        <magic priority="50">
+            <match type="string" value="{1}" offset="0"/>
+            <match type="string" value="{0}" offset="0"/>
+            <match type="string" value="}{" offset="0:6"/>
+        </magic>
+        <generic-icon name="text-x-generic"/>
+        <glob pattern="*.sub"/>
+        <glob pattern="*.txt"/>
+    </mime-type>
+</mime-info>
diff --git a/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp b/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
index 1a3256534b..4eb21b7659 100644
--- a/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
+++ b/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
@@ -49,6 +49,7 @@ static const char *const additionalMimeFiles[] = {
     "yast2-metapackage-handler-mimetypes.xml",
     "qml-again.xml",
     "text-x-objcsrc.xml",
+    "text-plain-subclass.xml",
     "invalid-magic1.xml",
     "invalid-magic2.xml",
     "invalid-magic3.xml",
@@ -1069,6 +1070,8 @@ void tst_QMimeDatabase::installNewLocalMimeType()
         QVERIFY(objcsrc.isValid());
         QCOMPARE(objcsrc.globPatterns(), QStringList());
     }
+    QCOMPARE(db.mimeTypeForFile(QLatin1String("foo.txt"), QMimeDatabase::MatchExtension).name(),
+             QString::fromLatin1("text/plain"));
 
     // Test that a double-definition of a mimetype doesn't lead to sniffing ("conflicting globs").
     const QString qmlTestFile = QLatin1String(RESOURCE_PREFIX "test.qml");
-- 
2.40.1