QPlugin: pass the direct header to qJsonFromRawLibraryMetaData()

This is done in preparation for storing the metadata without the magic
string in static plugins and in ELF notes.

Change-Id: I3eb1bd30e0124f89a052fffd16a820454dd56d3e
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 8 insertions, 1 deletions

diff --git a/src/corelib/plugin/qlibrary.cpp b/src/corelib/plugin/qlibrary.cpp
index f83a9483f4..1df6dfeb08 100644
--- a/src/corelib/plugin/qlibrary.cpp
+++ b/src/corelib/plugin/qlibrary.cpp
@@ -205,6 +205,7 @@ static QLibraryScanResult qt_find_pattern(const char *s, qsizetype s_len, QStrin
         *errMsg = QLibrary::tr("'%1' is not a Qt plugin").arg(*errMsg);
         return QLibraryScanResult{};
     }
+    i += sizeof(QPluginMetaData::MagicString);
     return { i, s_len - i };
 }
 
@@ -686,7 +687,13 @@ static bool qt_get_metadata(QLibraryPrivate *priv, QString *errMsg)
         return error(QLibrary::tr("entrypoint 'qt_plugin_query_metadata' not found"));
 
     auto metaData = reinterpret_cast<QPluginMetaData (*)()>(pfn)();
-    QJsonDocument doc = qJsonFromRawLibraryMetaData(reinterpret_cast<const char *>(metaData.data), metaData.size, errMsg);
+    auto data = reinterpret_cast<const char *>(metaData.data);
+    if (metaData.size < sizeof(QPluginMetaData::MagicHeader))
+        return error(QLibrary::tr("metadata too small"));
+
+    data += sizeof(QPluginMetaData::MagicString);
+    metaData.size -= sizeof(QPluginMetaData::MagicString);
+    QJsonDocument doc = qJsonFromRawLibraryMetaData(data, metaData.size, errMsg);
     if (doc.isNull())
         return false;           // error message already set