Issue #14909: A number of places were using PyMem_Realloc() apis and

PyObject_GC_Resize() with incorrect error handling.  In case of errors,
the original object would be leaked.  This checkin fixes those cases.

3 files changed, 12 insertions, 7 deletions

diff --git a/Modules/_localemodule.c b/Modules/_localemodule.c
index 20c59a4..cc688ba 100644
--- a/Modules/_localemodule.c
+++ b/Modules/_localemodule.c
@@ -257,11 +257,12 @@ PyLocale_strxfrm(PyObject* self, PyObject* args)
     n2 = wcsxfrm(buf, s, n1);
     if (n2 >= (size_t)n1) {
         /* more space needed */
-        buf = PyMem_Realloc(buf, (n2+1)*sizeof(wchar_t));
-        if (!buf) {
+        wchar_t * new_buf = PyMem_Realloc(buf, (n2+1)*sizeof(wchar_t));
+        if (!new_buf) {
             PyErr_NoMemory();
             goto exit;
         }
+        buf = new_buf;
         n2 = wcsxfrm(buf, s, n2+1);
     }
     result = PyUnicode_FromWideChar(buf, n2);
diff --git a/Modules/_randommodule.c b/Modules/_randommodule.c
index bc9b04a..3c7d700 100644
--- a/Modules/_randommodule.c
+++ b/Modules/_randommodule.c
@@ -210,7 +210,7 @@ random_seed(RandomObject *self, PyObject *args)
     PyObject *masklower = NULL;
     PyObject *thirtytwo = NULL;
     PyObject *n = NULL;
-    unsigned long *key = NULL;
+    unsigned long *new_key, *key = NULL;
     unsigned long keymax;               /* # of allocated slots in key */
     unsigned long keyused;              /* # of used slots in key */
     int err;
@@ -287,10 +287,11 @@ random_seed(RandomObject *self, PyObject *args)
                 PyErr_NoMemory();
                 goto Done;
             }
-            key = (unsigned long *)PyMem_Realloc(key,
+            new_key = (unsigned long *)PyMem_Realloc(key,
                                     bigger * sizeof(*key));
-            if (key == NULL)
+            if (new_key == NULL)
                 goto Done;
+            key = new_key;
             keymax = bigger;
         }
         assert(keyused < keymax);
diff --git a/Modules/unicodedata.c b/Modules/unicodedata.c
index ed79165..5c982f5 100644
--- a/Modules/unicodedata.c
+++ b/Modules/unicodedata.c
@@ -526,13 +526,16 @@ nfd_nfkd(PyObject *self, PyObject *input, int k)
             /* Hangul Decomposition adds three characters in
                a single step, so we need atleast that much room. */
             if (space < 3) {
+                Py_UCS4 *new_output;
                 osize += 10;
                 space += 10;
-                output = PyMem_Realloc(output, osize*sizeof(Py_UCS4));
-                if (output == NULL) {
+                new_output = PyMem_Realloc(output, osize*sizeof(Py_UCS4));
+                if (new_output == NULL) {
+                    PyMem_Free(output);
                     PyErr_NoMemory();
                     return NULL;
                 }
+                output = new_output;
             }
             /* Hangul Decomposition. */
             if (SBase <= code && code < (SBase+SCount)) {