commit 423a85a11a9d3d658906aea715fed7fe6aa83cd8
author Bram Moolenaar <Bram@vim.org> Sat Aug 29 12:57:16 2020 +0200
committer Bram Moolenaar <Bram@vim.org> Sat Aug 29 12:57:16 2020 +0200
tree e37cd64de2c0662552bba8ded601ebc3b00db093
parent b06a6d59d12dbd67d55b3c46f6e5547e9103c931

patch 8.2.1538: Python: iteration over vim objects fails to keep reference

Problem:    Python: iteration over vim objects fails to keep reference.
Solution:   Keep a reference for the object. (Paul Ollis, closes #6803,
            closes #6806)

src/if_py_both.h

diff --git a/src/if_py_both.h b/src/if_py_both.h
index 8eb7747..86942b6 100644
--- a/src/if_py_both.h
+++ b/src/if_py_both.h
@@ -1442,11 +1442,12 @@
     destructorfun destruct;
     traversefun traverse;
     clearfun clear;
+    PyObject *iter_object;
 } IterObject;
 
     static PyObject *
 IterNew(void *start, destructorfun destruct, nextfun next, traversefun traverse,
-	clearfun clear)
+	clearfun clear, PyObject *iter_object)
 {
     IterObject *self;
 
@@ -1456,6 +1457,10 @@
     self->destruct = destruct;
     self->traverse = traverse;
     self->clear = clear;
+    self->iter_object = iter_object;
+
+    if (iter_object)
+	Py_INCREF(iter_object);
 
     return (PyObject *)(self);
 }
@@ -1463,6 +1468,8 @@
     static void
 IterDestructor(IterObject *self)
 {
+    if (self->iter_object)
+	Py_DECREF(self->iter_object);
     PyObject_GC_UnTrack((void *)(self));
     self->destruct(self->cur);
     PyObject_GC_Del((void *)(self));
@@ -1844,7 +1851,7 @@
 
     return IterNew(dii,
 	    (destructorfun) PyMem_Free, (nextfun) DictionaryIterNext,
-	    NULL, NULL);
+	    NULL, NULL, (PyObject *)self);
 }
 
     static PyInt
@@ -2842,7 +2849,7 @@
 
     return IterNew(lii,
 	    (destructorfun) ListIterDestruct, (nextfun) ListIterNext,
-	    NULL, NULL);
+	    NULL, NULL, (PyObject *)self);
 }
 
 static char *ListAttrs[] = {
@@ -3491,7 +3498,7 @@
 
     return IterNew(oii,
 	    (destructorfun) PyMem_Free, (nextfun) OptionsIterNext,
-	    NULL, NULL);
+	    NULL, NULL, (PyObject *)self);
 }
 
     static int
@@ -5488,14 +5495,15 @@
 }
 
     static PyObject *
-BufMapIter(PyObject *self UNUSED)
+BufMapIter(PyObject *self)
 {
     PyObject *buffer;
 
     buffer = BufferNew(firstbuf);
     return IterNew(buffer,
 	    (destructorfun) BufMapIterDestruct, (nextfun) BufMapIterNext,
-	    (traversefun) BufMapIterTraverse, (clearfun) BufMapIterClear);
+	    (traversefun) BufMapIterTraverse, (clearfun) BufMapIterClear,
+	    (PyObject *)self);
 }
 
 static PyMappingMethods BufMapAsMapping = {