Use potentially intercepted URL as ID for compilation units

We generally have to pass a URL and a file name everywhere because the
logical URL might be something else than the actual file being loaded.
For example a QQmlFileSelector might modify the URL to be loaded for a
specific file. This resulting URL, however, should not be used to
resolve further URLs defined in the file loaded that way.

As we need to access QQmlTypeLoader::m_url as string more often now,
cache it and avoid frequent translations between QUrl and QString.

Furthermore, QQmlDataBlob's URLs are changed to follow the same
semantics. The finalUrl is the one that should be used to resolve
further URLs, the url is the one used to load the content, and subject
to any redirects or interceptions.

This changes the semantics of URL redirects. Previously a redirected URL
was used as the base URL for furher URL resolution. This doesn't work
because redirection occurs after interception and interception should
not influence the resolution of further URLs. We now use the original
URL as base URL for resolution of further URLs and rely on the server to
redirect those, too.

Task-number: QTBUG-61209
Change-Id: I93822f820bed2515995de3cb118099218b510ca4
Reviewed-by: Michael Brasser <michael.brasser@live.com>

1 files changed, 20 insertions, 2 deletions

diff --git a/src/qml/compiler/qv4compileddata_p.h b/src/qml/compiler/qv4compileddata_p.h
index 440dc3e013..188a571394 100644
--- a/src/qml/compiler/qv4compileddata_p.h
+++ b/src/qml/compiler/qv4compileddata_p.h
@@ -72,7 +72,7 @@
 QT_BEGIN_NAMESPACE
 
 // Bump this whenever the compiler data structures change in an incompatible way.
-#define QV4_DATA_STRUCTURE_VERSION 0x13
+#define QV4_DATA_STRUCTURE_VERSION 0x14
 
 class QIODevice;
 class QQmlPropertyCache;
@@ -661,6 +661,7 @@ struct Unit
     LEUInt32 offsetToJSClassTable;
     LEInt32 indexOfRootFunction;
     LEUInt32 sourceFileIndex;
+    LEUInt32 finalUrlIndex;
 
     /* QML specific fields */
     LEUInt32 nImports;
@@ -668,6 +669,8 @@ struct Unit
     LEUInt32 nObjects;
     LEUInt32 offsetToObjects;
 
+    LEUInt32 padding;
+
     const Import *importAt(int idx) const {
         return reinterpret_cast<const Import*>((reinterpret_cast<const char *>(this)) + offsetToImports + idx * sizeof(Import));
     }
@@ -732,7 +735,7 @@ struct Unit
     }
 };
 
-static_assert(sizeof(Unit) == 144, "Unit structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+static_assert(sizeof(Unit) == 152, "Unit structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct TypeReference
 {
@@ -842,14 +845,29 @@ struct Q_QML_PRIVATE_EXPORT CompilationUnit : public CompilationUnitBase, public
     ExecutionEngine *engine;
     QQmlEnginePrivate *qmlEngine; // only used in QML environment for composite types, not in plain QJSEngine case.
 
+    // url() and fileName() shall be used to load the actual QML/JS code or to show errors or
+    // warnings about that code. They include any potential URL interceptions and thus represent the
+    // "physical" location of the code.
+    //
+    // finalUrl() and finalUrlString() shall be used to resolve further URLs referred to in the code
+    // They are _not_ intercepted and thus represent the "logical" name for the code.
+
     QString fileName() const { return data->stringAt(data->sourceFileIndex); }
+    QString finalUrlString() const { return data->stringAt(data->finalUrlIndex); }
     QUrl url() const { if (m_url.isNull) m_url = QUrl(fileName()); return m_url; }
+    QUrl finalUrl() const
+    {
+        if (m_finalUrl.isNull)
+            m_finalUrl = QUrl(finalUrlString());
+        return m_finalUrl;
+    }
 
     QV4::Lookup *runtimeLookups;
     QV4::Value *runtimeRegularExpressions;
     QV4::InternalClass **runtimeClasses;
     QVector<QV4::Function *> runtimeFunctions;
     mutable QQmlNullableValue<QUrl> m_url;
+    mutable QQmlNullableValue<QUrl> m_finalUrl;
 
     // QML specific fields
     QQmlPropertyCacheVector propertyCaches;