Fix [ 616716 ] Bug in PyErr_SetExcFromWindows
Ensure that even if FormatMessage fails we (a) don't crash, and (b) provide something useful.
Bugfix candidate.
diff --git a/Python/errors.c b/Python/errors.c
index 9a2597b..95c24a6 100644
--- a/Python/errors.c
+++ b/Python/errors.c
@@ -269,6 +269,7 @@
#endif
#ifdef MS_WINDOWS
char *s_buf = NULL;
+ char s_small_buf[28]; /* Room for "Windows Error 0xFFFFFFFF" */
#endif
#ifdef EINTR
if (i == EINTR && PyErr_CheckSignals())
@@ -306,10 +307,18 @@
(LPTSTR) &s_buf,
0, /* size not used */
NULL); /* no args */
- s = s_buf;
- /* remove trailing cr/lf and dots */
- while (len > 0 && (s[len-1] <= ' ' || s[len-1] == '.'))
- s[--len] = '\0';
+ if (len==0) {
+ /* Only ever seen this in out-of-mem
+ situations */
+ sprintf(s_small_buf, "Windows Error 0x%X", i);
+ s = s_small_buf;
+ s_buf = NULL;
+ } else {
+ s = s_buf;
+ /* remove trailing cr/lf and dots */
+ while (len > 0 && (s[len-1] <= ' ' || s[len-1] == '.'))
+ s[--len] = '\0';
+ }
}
}
#endif /* Unix/Windows */
@@ -366,6 +375,8 @@
{
int len;
char *s;
+ char *s_buf = NULL; /* Free via LocalFree */
+ char s_small_buf[28]; /* Room for "Windows Error 0xFFFFFFFF" */
PyObject *v;
DWORD err = (DWORD)ierr;
if (err==0) err = GetLastError();
@@ -378,12 +389,20 @@
err,
MAKELANGID(LANG_NEUTRAL,
SUBLANG_DEFAULT), /* Default language */
- (LPTSTR) &s,
+ (LPTSTR) &s_buf,
0, /* size not used */
NULL); /* no args */
- /* remove trailing cr/lf and dots */
- while (len > 0 && (s[len-1] <= ' ' || s[len-1] == '.'))
- s[--len] = '\0';
+ if (len==0) {
+ /* Only seen this in out of mem situations */
+ sprintf(s_small_buf, "Windows Error 0x%X", err);
+ s = s_small_buf;
+ s_buf = NULL;
+ } else {
+ s = s_buf;
+ /* remove trailing cr/lf and dots */
+ while (len > 0 && (s[len-1] <= ' ' || s[len-1] == '.'))
+ s[--len] = '\0';
+ }
if (filenameObject != NULL)
v = Py_BuildValue("(isO)", err, s, filenameObject);
else
@@ -392,7 +411,7 @@
PyErr_SetObject(exc, v);
Py_DECREF(v);
}
- LocalFree(s);
+ LocalFree(s_buf);
return NULL;
}