Issue #15604: Update uses of PyObject_IsTrue() to check for and handle errors correctly.

Patch by Serhiy Storchaka.

2 files changed, 14 insertions, 3 deletions

diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 232e3dc..0e90490 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -428,9 +428,11 @@ filter_next(filterobject *lz)
             ok = PyObject_IsTrue(good);
             Py_DECREF(good);
         }
-        if (ok)
+        if (ok > 0)
             return item;
         Py_DECREF(item);
+        if (ok < 0)
+            return NULL;
     }
 }
 
diff --git a/Python/import.c b/Python/import.c
index 598b7e0..beb0eec 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -1338,7 +1338,10 @@ load_source_module(char *name, char *pathname, FILE *fp)
                 name, pathname);
         if (cpathname) {
             PyObject *ro = PySys_GetObject("dont_write_bytecode");
-            if (ro == NULL || !PyObject_IsTrue(ro))
+            int b = (ro == NULL) ? 0 : PyObject_IsTrue(ro);
+            if (b < 0)
+                goto error_exit;
+            if (!b)
                 write_compiled_module(co, cpathname, &st);
         }
     }
@@ -2504,7 +2507,13 @@ import_module_level(char *name, PyObject *globals, PyObject *locals,
     }
 
     if (fromlist != NULL) {
-        if (fromlist == Py_None || !PyObject_IsTrue(fromlist))
+        int b = (fromlist == Py_None) ? 0 : PyObject_IsTrue(fromlist);
+        if (b < 0) {
+            Py_DECREF(tail);
+            Py_DECREF(head);
+            goto error_exit;
+        }
+        if (!b)
             fromlist = NULL;
     }