Merge branch 'dl/rebase-i-keep-base'

diff --git a/cache.h b/cache.h
index 3cbad5b603ec03ce9e4ec26be84de653e049c980..5624e6c02d5e72ab2975bb3219329e4580f96f55 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -636,6 +636,9 @@ int daemonize(void);
  * at least 'nr' entries; the number of entries currently allocated
  * is 'alloc', using the standard growing factor alloc_nr() macro.
  *
+ * Consider using ALLOC_GROW_BY instead of ALLOC_GROW as it has some
+ * added niceties.
+ *
  * DO NOT USE any expression with side-effect for 'x', 'nr', or 'alloc'.
  */
 #define ALLOC_GROW(x, nr, alloc) \
@@ -649,6 +652,25 @@ int daemonize(void);
                } \
        } while (0)
 
+/*
+ * Similar to ALLOC_GROW but handles updating of the nr value and
+ * zeroing the bytes of the newly-grown array elements.
+ *
+ * DO NOT USE any expression with side-effect for any of the
+ * arguments.
+ */
+#define ALLOC_GROW_BY(x, nr, increase, alloc) \
+       do { \
+               if (increase) { \
+                       size_t new_nr = nr + (increase); \
+                       if (new_nr < nr) \
+                               BUG("negative growth in ALLOC_GROW_BY"); \
+                       ALLOC_GROW(x, new_nr, alloc); \
+                       memset((x) + nr, 0, sizeof(*(x)) * (increase)); \
+                       nr = new_nr; \
+               } \
+       } while (0)
+
 /* Initialize and use the cache information */
 struct lock_file;
 void preload_index(struct index_state *index,