ldap: fix OOM check

[nico-abram]

Should Fix #4261

This just applies the changes described in #4261 (comment)

I tested before and after on windows 7 64 bit, it gave me the OOM message before, and the expected output after the change.

[bagder]

Thanks! I just find it a little bit weird to strdup() the pointer if it is NULL and check for NULL after the fact. How about instead doing something like below, to make it a little more readable?

--- a/lib/ldap.c
+++ b/lib/ldap.c
@@ -845,11 +845,11 @@ static int _ldap_url_parse2(const struct connectdata *conn, LDAPURLDesc *ludp)
 {
   int rc = LDAP_SUCCESS;
   char *path;
   char *query;
   char *p;
-  char *q;
+  char *q = NULL;
   size_t i;
 
   if(!conn->data ||
      !conn->data->state.up.path ||
      conn->data->state.up.path[0] != '/' ||
@@ -863,15 +863,17 @@ static int _ldap_url_parse2(const struct connectdata *conn, LDAPURLDesc *ludp)
   /* Duplicate the path */
   p = path = strdup(conn->data->state.up.path + 1);
   if(!path)
     return LDAP_NO_MEMORY;
 
-  /* Duplicate the query */
-  q = query = strdup(conn->data->state.up.query);
-  if(!query) {
-    free(path);
-    return LDAP_NO_MEMORY;
+  /* Duplicate the query if present */
+  if(conn->data->state.up.query) {
+    q = query = strdup(conn->data->state.up.query);
+    if(!query) {
+      free(path);
+      return LDAP_NO_MEMORY;
+    }
   }
 
   /* Parse the DN (Distinguished Name) */
   if(*p) {
     char *dn = p;

[nico-abram]

You're absolutely right, thank you for the review!

I force pushed the changes so as to not make it two commits.

[jay]

Thanks. I modified the commit to say this is a partial fix for #4261 which I think is two bugs, and this fixes one of them. Also I changed add init query NULL because later in cleanup there's free(query).