Merge branch 'rs/move-array' into maint

Code clean-up.

* rs/move-array:
  ls-files: don't try to prune an empty index
  apply: use COPY_ARRAY and MOVE_ARRAY in update_image()
  use MOVE_ARRAY
  add MOVE_ARRAY

apply.c

@@ -2809,13 +2809,10 @@ static void update_image(struct apply_state *state,
 		img->line_allocated = img->line;
 	}
 	if (preimage_limit != postimage->nr)
-		memmove(img->line + applied_pos + postimage->nr,
-			img->line + applied_pos + preimage_limit,
-			(img->nr - (applied_pos + preimage_limit)) *
-			sizeof(*img->line));
-	memcpy(img->line + applied_pos,
-	       postimage->line,
-	       postimage->nr * sizeof(*img->line));
+		MOVE_ARRAY(img->line + applied_pos + postimage->nr,
+			   img->line + applied_pos + preimage_limit,
+			   img->nr - (applied_pos + preimage_limit));
+	COPY_ARRAY(img->line + applied_pos, postimage->line, postimage->nr);
 	if (!state->allow_overlap)
 		for (i = 0; i < postimage->nr; i++)
 			img->line[applied_pos + i].flag |= LINE_PATCHED;

builtin/ls-files.c

@@ -362,7 +362,7 @@ static void prune_index(struct index_state *istate,
 	int pos;
 	unsigned int first, last;
 
-	if (!prefix)
+	if (!prefix || !istate->cache_nr)
 		return;
 	pos = index_name_pos(istate, prefix, prefixlen);
 	if (pos < 0)
@@ -378,8 +378,7 @@ static void prune_index(struct index_state *istate,
 		}
 		last = next;
 	}
-	memmove(istate->cache, istate->cache + pos,
-		(last - pos) * sizeof(struct cache_entry *));
+	MOVE_ARRAY(istate->cache, istate->cache + pos, last - pos);
 	istate->cache_nr = last - pos;
 }
 

builtin/merge.c

@@ -537,7 +537,7 @@ static void parse_branch_merge_options(char *bmo)
 		die(_("Bad branch.%s.mergeoptions string: %s"), branch,
 		    split_cmdline_strerror(argc));
 	REALLOC_ARRAY(argv, argc + 2);
-	memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
+	MOVE_ARRAY(argv + 1, argv, argc + 1);
 	argc++;
 	argv[0] = "branch.*.mergeoptions";
 	parse_options(argc, argv, NULL, builtin_merge_options,

builtin/pack-objects.c

@@ -1298,9 +1298,8 @@ static int check_pbase_path(unsigned hash)
 		   done_pbase_paths_alloc);
 	done_pbase_paths_num++;
 	if (pos < done_pbase_paths_num)
-		memmove(done_pbase_paths + pos + 1,
-			done_pbase_paths + pos,
-			(done_pbase_paths_num - pos - 1) * sizeof(unsigned));
+		MOVE_ARRAY(done_pbase_paths + pos + 1, done_pbase_paths + pos,
+			   done_pbase_paths_num - pos - 1);
 	done_pbase_paths[pos] = hash;
 	return 0;
 }

cache-tree.c

@@ -131,9 +131,8 @@ static int do_invalidate_path(struct cache_tree *it, const char *path)
 			 * move 4 and 5 up one place (2 entries)
 			 * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
 			 */
-			memmove(it->down+pos, it->down+pos+1,
-				sizeof(struct cache_tree_sub *) *
-				(it->subtree_nr - pos - 1));
+			MOVE_ARRAY(it->down + pos, it->down + pos + 1,
+				   it->subtree_nr - pos - 1);
 			it->subtree_nr--;
 		}
 		return 1;

commit.c

@@ -223,9 +223,8 @@ int unregister_shallow(const struct object_id *oid)
 	if (pos < 0)
 		return -1;
 	if (pos + 1 < commit_graft_nr)
-		memmove(commit_graft + pos, commit_graft + pos + 1,
-				sizeof(struct commit_graft *)
-				* (commit_graft_nr - pos - 1));
+		MOVE_ARRAY(commit_graft + pos, commit_graft + pos + 1,
+			   commit_graft_nr - pos - 1);
 	commit_graft_nr--;
 	return 0;
 }

contrib/coccinelle/array.cocci

@@ -25,6 +25,23 @@ expression n;
 - memcpy(dst, src, n * sizeof(T));
 + COPY_ARRAY(dst, src, n);
 
+@@
+type T;
+T *dst;
+T *src;
+expression n;
+@@
+(
+- memmove(dst, src, (n) * sizeof(*dst));
++ MOVE_ARRAY(dst, src, n);
+|
+- memmove(dst, src, (n) * sizeof(*src));
++ MOVE_ARRAY(dst, src, n);
+|
+- memmove(dst, src, (n) * sizeof(T));
++ MOVE_ARRAY(dst, src, n);
+)
+
 @@
 type T;
 T *ptr;

git-compat-util.h

@@ -828,6 +828,14 @@ static inline void copy_array(void *dst, const void *src, size_t n, size_t size)
 		memcpy(dst, src, st_mult(size, n));
 }
 
+#define MOVE_ARRAY(dst, src, n) move_array((dst), (src), (n), sizeof(*(dst)) + \
+	BUILD_ASSERT_OR_ZERO(sizeof(*(dst)) == sizeof(*(src))))
+static inline void move_array(void *dst, const void *src, size_t n, size_t size)
+{
+	if (n)
+		memmove(dst, src, st_mult(size, n));
+}
+
 /*
  * These functions help you allocate structs with flex arrays, and copy
  * the data directly into the array. For example, if you had:

notes-merge.c

@@ -99,8 +99,7 @@ static struct notes_merge_pair *find_notes_merge_pair_pos(
 	else {
 		*occupied = 0;
 		if (insert_new && i < len) {
-			memmove(list + i + 1, list + i,
-				(len - i) * sizeof(struct notes_merge_pair));
+			MOVE_ARRAY(list + i + 1, list + i, len - i);
 			memset(list + i, 0, sizeof(struct notes_merge_pair));
 		}
 	}

read-cache.c

@@ -515,9 +515,8 @@ int remove_index_entry_at(struct index_state *istate, int pos)
 	istate->cache_nr--;
 	if (pos >= istate->cache_nr)
 		return 0;
-	memmove(istate->cache + pos,
-		istate->cache + pos + 1,
-		(istate->cache_nr - pos) * sizeof(struct cache_entry *));
+	MOVE_ARRAY(istate->cache + pos, istate->cache + pos + 1,
+		   istate->cache_nr - pos);
 	return 1;
 }
 

string-list.c

@@ -43,9 +43,8 @@ static int add_entry(int insert_at, struct string_list *list, const char *string
 
 	ALLOC_GROW(list->items, list->nr+1, list->alloc);
 	if (index < list->nr)
-		memmove(list->items + index + 1, list->items + index,
-				(list->nr - index)
-				* sizeof(struct string_list_item));
+		MOVE_ARRAY(list->items + index + 1, list->items + index,
+			   list->nr - index);
 	list->items[index].string = list->strdup_strings ?
 		xstrdup(string) : (char *)string;
 	list->items[index].util = NULL;
@@ -77,8 +76,7 @@ void string_list_remove(struct string_list *list, const char *string,
 			free(list->items[i].util);
 
 		list->nr--;
-		memmove(list->items + i, list->items + i + 1,
-			(list->nr - i) * sizeof(struct string_list_item));
+		MOVE_ARRAY(list->items + i, list->items + i + 1, list->nr - i);
 	}
 }