[python] Block imports of PyQt4 modules

Prevents crashes when PyQt4 modules are imported in QGIS 3.x. This instantly segfaults QGIS. Throwing an exception makes it easier to identify the cause as a faulty plugin, and shows exactly where the bad import is located.
qgis · Jun 29, 2018 · dbac3b4 · dbac3b4
1 parent 0c0981a
commit dbac3b4
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/python/utils.py b/python/utils.py
@@ -659,9 +659,16 @@ def __exit__(self, exc_type, exc_val, exc_tb):
 
 
 def _import(name, globals={}, locals={}, fromlist=[], level=None):
-    """ wrapper around builtin import that keeps track of loaded plugin modules """
+    """
+    Wrapper around builtin import that keeps track of loaded plugin modules and blocks
+    certain unsafe imports
+    """
     if level is None:
         level = 0
+
+    if 'PyQt4' in name:
+        raise ImportError('Cannot import PyQt4 classes - this would cause a crash!')
+
     mod = _builtin_import(name, globals, locals, fromlist, level)
 
     if mod and '__file__' in mod.__dict__: