Python: Ignore from foo import * when foo is absent.

Author: tausbn

python/ql/src/Imports/UnintentionalImport.ql

@@ -26,7 +26,7 @@ predicate all_defined(ModuleValue exporter) {
 }
 
 from ImportStar imp, ModuleValue exporter
-where import_star(imp, exporter) and not all_defined(exporter)
+where import_star(imp, exporter) and not all_defined(exporter) and not exporter.isAbsent()
 select imp,
   "Import pollutes the enclosing namespace, as the imported module $@ does not define '__all__'.",
   exporter, exporter.getName()

python/ql/test/query-tests/Imports/general/UnintentionalImport.expected

@@ -1,2 +1 @@
 | imports_test.py:22:1:22:32 | from module_without_all import * | Import pollutes the enclosing namespace, as the imported module $@ does not define '__all__'. | module_without_all.py:0:0:0:0 | Module module_without_all | module_without_all |
-| imports_test.py:65:1:65:40 | from module_that_does_not_exist import * | Import pollutes the enclosing namespace, as the imported module $@ does not define '__all__'. | file://:0:0:0:0 | Missing module module_that_does_not_exist | module_that_does_not_exist |