Merge branch 'maint'

* maint:
  unpack_trees(): protect the handcrafted in-core index from read_cache()
  git-p4: Fix one-liner in p4_write_pipe function.
  Completion: add missing '=' for 'diff --diff-filter'
  Fix 'git help help'

cache.h

@@ -223,7 +223,8 @@ struct index_state {
 	struct cache_tree *cache_tree;
 	time_t timestamp;
 	void *alloc;
-	unsigned name_hash_initialized : 1;
+	unsigned name_hash_initialized : 1,
+		 initialized : 1;
 	struct hash_table name_hash;
 };
 

contrib/completion/git-completion.bash

@@ -771,7 +771,7 @@ _git_diff ()
 		__gitcomp "--cached --stat --numstat --shortstat --summary
 			--patch-with-stat --name-only --name-status --color
 			--no-color --color-words --no-renames --check
-			--full-index --binary --abbrev --diff-filter
+			--full-index --binary --abbrev --diff-filter=
 			--find-copies-harder --pickaxe-all --pickaxe-regex
 			--text --ignore-space-at-eol --ignore-space-change
 			--ignore-all-space --exit-code --quiet --ext-diff

contrib/fast-import/git-p4

@@ -76,7 +76,7 @@ def write_pipe(c, str):
 
 def p4_write_pipe(c, str):
     real_cmd = p4_build_cmd(c)
-    return write_pipe(c, str)
+    return write_pipe(real_cmd, str)
 
 def read_pipe(c, ignore_error=False):
     if verbose:

help.c

@@ -555,7 +555,8 @@ static int is_git_command(const char *s)
 {
 	load_command_list();
 	return is_in_cmdlist(&main_cmds, s) ||
-		is_in_cmdlist(&other_cmds, s);
+		is_in_cmdlist(&other_cmds, s) ||
+		!strcmp(s, "help");
 }
 
 static const char *prepend(const char *prefix, const char *cmd)

read-cache.c

@@ -1159,7 +1159,7 @@ int read_index_from(struct index_state *istate, const char *path)
 	size_t mmap_size;
 
 	errno = EBUSY;
-	if (istate->alloc)
+	if (istate->initialized)
 		return istate->cache_nr;
 
 	errno = ENOENT;
@@ -1199,6 +1199,7 @@ int read_index_from(struct index_state *istate, const char *path)
 	 * index size
 	 */
 	istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));
+	istate->initialized = 1;
 
 	src_offset = sizeof(*hdr);
 	dst_offset = 0;
@@ -1251,6 +1252,7 @@ int discard_index(struct index_state *istate)
 	cache_tree_free(&(istate->cache_tree));
 	free(istate->alloc);
 	istate->alloc = NULL;
+	istate->initialized = 0;
 
 	/* no need to throw away allocated active_cache */
 	return 0;

unpack-trees.c

@@ -376,6 +376,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 	state.refresh_cache = 1;
 
 	memset(&o->result, 0, sizeof(o->result));
+	o->result.initialized = 1;
 	if (o->src_index)
 		o->result.timestamp = o->src_index->timestamp;
 	o->merge_size = len;