QQmlImport: Handle file selectors in qmldir

With file selectors, a type can exist in the same version under
different paths. Detect this case, canonicalize the filename to the
selector free version, and rely on the engine to resolve a URL to the
correct file.

Fixes: QTBUG-107797
Change-Id: I0f74fd37936abfa08547fb439bfa5264e6ca4787
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
(cherry picked from commit 9bfb27be010940ca735ca7dd67a092a03289e27c)
Reviewed-by: Sami Shalayel <sami.shalayel@qt.io>

1 files changed, 60 insertions, 0 deletions

diff --git a/src/qml/qml/qqmlimport.cpp b/src/qml/qml/qqmlimport.cpp
index 611ff42681..5e60f9fb95 100644
--- a/src/qml/qml/qqmlimport.cpp
+++ b/src/qml/qml/qqmlimport.cpp
@@ -1169,6 +1169,26 @@ QString QQmlImportsPrivate::resolvedUri(const QString &dir_arg, QQmlImportDataba
     return stableRelativePath;
 }
 
+/* removes all file selector occurrences in path
+   firstPlus is the position of the initial '+' in the path
+   which we always have as we check for '+' to decide whether
+   we need to do some work at all
+*/
+static QString pathWithoutFileSelectors(QString path, // we want a copy of path
+                                        qsizetype firstPlus)
+{
+    do {
+        Q_ASSERT(path.at(firstPlus) == u'+');
+        const auto eos = path.size();
+        qsizetype terminatingSlashPos = firstPlus + 1;
+        while (terminatingSlashPos != eos && path.at(terminatingSlashPos) != u'/')
+            ++terminatingSlashPos;
+        path.remove(firstPlus, terminatingSlashPos - firstPlus + 1);
+        firstPlus = path.indexOf(u'+', firstPlus);
+    } while (firstPlus != -1);
+    return path;
+}
+
 /*!
   \internal
 
@@ -1215,10 +1235,42 @@ QTypeRevision QQmlImportsPrivate::matchingQmldirVersion(
     typedef QQmlDirComponents::const_iterator ConstIterator;
     const QQmlDirComponents &components = qmldir.components();
 
+    QMultiHash<QString, ConstIterator> baseFileName2ConflictingComponents;
+
     ConstIterator cend = components.constEnd();
     for (ConstIterator cit = components.constBegin(); cit != cend; ++cit) {
         for (ConstIterator cit2 = components.constBegin(); cit2 != cit; ++cit2) {
             if (cit2->typeName == cit->typeName && cit2->version == cit->version) {
+                // ugly heuristic to deal with file selectors
+                const auto comp2PotentialFileSelectorPos = cit2->fileName.indexOf(u'+');
+                const bool comp2MightHaveFileSelector = comp2PotentialFileSelectorPos != -1;
+                /* If we detect conflicting paths, we check if they agree when we remove anything looking like a
+                   file selector.
+                   We need to create copies of the filenames, otherwise QString::replace would modify the
+                   existing file-names
+                 */
+                QString compFileName1 = cit->fileName;
+                QString compFileName2 = cit2->fileName;
+                if (auto fileSelectorPos1 = compFileName1.indexOf(u'+'); fileSelectorPos1 != -1) {
+                    // existing entry was file selector entry, fix it up
+                    // it could also be the case that _both_ are using file selectors
+                    QString baseName =  comp2MightHaveFileSelector ? pathWithoutFileSelectors(compFileName2,
+                                                                                         comp2PotentialFileSelectorPos)
+                                                                   : compFileName2;
+                    if (pathWithoutFileSelectors(compFileName1, fileSelectorPos1) == baseName) {
+                        baseFileName2ConflictingComponents.insert(baseName, cit);
+                        baseFileName2ConflictingComponents.insert(baseName, cit2);
+                        continue;
+                    }
+                    // fall through to error case
+                } else if (comp2MightHaveFileSelector) {
+                    // new entry contains file selector (and we now that cit did not)
+                    if (pathWithoutFileSelectors(compFileName2, comp2PotentialFileSelectorPos) == compFileName1) {
+                        baseFileName2ConflictingComponents.insert(compFileName1, cit2);
+                        continue;
+                    }
+                    // fall through to error case
+                }
                 // This entry clashes with a predecessor
                 QQmlError error;
                 error.setDescription(QQmlImportDatabase::tr("\"%1\" version %2.%3 is defined more than once in module \"%4\"")
@@ -1232,6 +1284,14 @@ QTypeRevision QQmlImportsPrivate::matchingQmldirVersion(
         addVersion(cit->version);
     }
 
+    // ensure that all components point to the actual base URL, and let the file selectors resolve them correctly during URL resolution
+    for (auto keyIt = baseFileName2ConflictingComponents.keyBegin(); keyIt != baseFileName2ConflictingComponents.keyEnd(); ++keyIt) {
+        const QString& baseFileName = *keyIt;
+        const auto conflictingComponents = baseFileName2ConflictingComponents.values(baseFileName);
+        for (ConstIterator component: conflictingComponents)
+            component->fileName = baseFileName;
+    }
+
     typedef QList<QQmlDirParser::Script>::const_iterator SConstIterator;
     const QQmlDirScripts &scripts = qmldir.scripts();