--- projects/libstatgrab/src/libstatgrab/vector.h	2004/04/05 00:20:05	1.3
+++ projects/libstatgrab/src/libstatgrab/vector.h	2004/04/05 00:45:17	1.4
@@ -22,8 +22,18 @@ typedef struct {
 		(vector_destroy_function) destroy_fn \
 	}
 
-int statgrab_vector_resize(char **vector, vector_header *h, int count);
+/* A pointer value that won't be returned by malloc, and isn't NULL, so can be
+ * used as a sentinel by allocation routines that need to return NULL
+ * sometimes. */
+extern char statgrab_vector_sentinel_value;
+static void *statgrab_vector_sentinel = &statgrab_vector_sentinel_value;
 
+/* Internal function to resize the vector. Ideally it would take void ** as the
+ * first parameter, but ANSI strict-aliasing rules would then prevent it from
+ * doing anything with it, so we return a sentinel value as above instead if
+ * allocation fails. */
+void *statgrab_vector_resize(void *vector, vector_header *h, int count);
+
 /* Declare a vector. Specify the init/destroy functions as NULL if you don't
  * need them. The block size is how many items to allocate at once. */
 #define VECTOR_DECLARE(name, item_type, block_size, init_fn, destroy_fn) \
@@ -41,9 +51,13 @@ int statgrab_vector_resize(char **vector, vector_heade
 
 /* Resize a vector. Returns 0 on success, -1 on out-of-memory. On
  * out-of-memory, the old contents of the vector will be destroyed and the old
- * vector will be freed. */
+ * vector will be freed.
+ *
+ * This is ugly because it needs to check for the sentinel value.
+ */
 #define VECTOR_RESIZE(name, num_items) \
-	statgrab_vector_resize((char **) &name, &name##_header, num_items)
+	(((name = statgrab_vector_resize((char *) name, &name##_header, num_items)) \
+	  == statgrab_vector_sentinel) ? -1 : 0)
 
 /* Free a vector, destroying its contents. */
 #define VECTOR_FREE(name) \