libcli/auth: let msrpc_parse() return talloc'ed empty strings

This make it more predictable for the callers.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11912
BUG: https://bugzilla.redhat.com/show_bug.cgi?id=1334356
BUG: https://launchpad.net/bugs/1578576

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Autobuild-User(master): Stefan Metzmacher <metze@samba.org>
Autobuild-Date(master): Mon May  9 22:27:21 CEST 2016 on sn-devel-144

(cherry picked from commit 58a83236294117d32d9883ac3024f81fa1730a87)

Autobuild-User(v4-2-test): Karolin Seeger <kseeger@samba.org>
Autobuild-Date(v4-2-test): Tue May 17 13:47:41 CEST 2016 on sn-devel-104

diff --git a/libcli/auth/msrpc_parse.c b/libcli/auth/msrpc_parse.c
index d499d9eb7a1f8bc60fe9568d685f60e1f720d8ca..74a7bcc27a8e8110367fbe6df68b02062bb00f60 100644 (file)
--- a/libcli/auth/msrpc_parse.c
+++ b/libcli/auth/msrpc_parse.c
@@ -262,7 +262,11 @@ bool msrpc_parse(TALLOC_CTX *mem_ctx,
 
                        ps = va_arg(ap, char **);
                        if (len1 == 0 && len2 == 0) {
-                               *ps = (char *)discard_const("");
+                               *ps = talloc_strdup(mem_ctx, "");
+                               if (*ps == NULL) {
+                                       ret = false;
+                                       goto cleanup;
+                               }
                        } else {
                                /* make sure its in the right format - be strict */
                                if ((len1 != len2) || (ptr + len1 < ptr) || (ptr + len1 < len1) || (ptr + len1 > blob->length)) {
@@ -289,7 +293,11 @@ bool msrpc_parse(TALLOC_CTX *mem_ctx,
                                                goto cleanup;
                                        }
                                } else {
-                                       (*ps) = (char *)discard_const("");
+                                       *ps = talloc_strdup(mem_ctx, "");
+                                       if (*ps == NULL) {
+                                               ret = false;
+                                               goto cleanup;
+                                       }
                                }
                        }
                        break;
@@ -302,7 +310,11 @@ bool msrpc_parse(TALLOC_CTX *mem_ctx,
                        ps = (char **)va_arg(ap, char **);
                        /* make sure its in the right format - be strict */
                        if (len1 == 0 && len2 == 0) {
-                               *ps = (char *)discard_const("");
+                               *ps = talloc_strdup(mem_ctx, "");
+                               if (*ps == NULL) {
+                                       ret = false;
+                                       goto cleanup;
+                               }
                        } else {
                                if ((len1 != len2) || (ptr + len1 < ptr) || (ptr + len1 < len1) || (ptr + len1 > blob->length)) {
                                        ret = false;
@@ -325,7 +337,11 @@ bool msrpc_parse(TALLOC_CTX *mem_ctx,
                                                goto cleanup;
                                        }
                                } else {
-                                       (*ps) = (char *)discard_const("");
+                                       *ps = talloc_strdup(mem_ctx, "");
+                                       if (*ps == NULL) {
+                                               ret = false;
+                                               goto cleanup;
+                                       }
                                }
                        }
                        break;