Merge branch 'jn/add-2.0-u-A-sans-pathspec' (early part)

In Git 2.0, "git add -u" and "git add -A" without any pathspec will
update the index for all paths, including those outside the current
directory, making it more consistent with "commit -a".  To help the
migration pain, a warning is issued when the differences between the
current behaviour and the upcoming behaviour matters, i.e. when the
user has local changes outside the current directory.

* 'jn/add-2.0-u-A-sans-pathspec' (early part):
  add -A: only show pathless 'add -A' warning when changes exist outside cwd
  add -u: only show pathless 'add -u' warning when changes exist outside cwd
  add: make warn_pathless_add() a no-op after first call
  add: add a blank line at the end of pathless 'add [-u|-A]' warning
  add: make pathless 'add [-u|-A]' warning a file-global function

Author: gitster

builtin/add.c

@@ -26,8 +26,52 @@ static int take_worktree_changes;
 struct update_callback_data {
 	int flags;
 	int add_errors;
+	const char *implicit_dot;
+	size_t implicit_dot_len;
 };
 
+static const char *option_with_implicit_dot;
+static const char *short_option_with_implicit_dot;
+
+static void warn_pathless_add(void)
+{
+	static int shown;
+	assert(option_with_implicit_dot && short_option_with_implicit_dot);
+
+	if (shown)
+		return;
+	shown = 1;
+
+	/*
+	 * To be consistent with "git add -p" and most Git
+	 * commands, we should default to being tree-wide, but
+	 * this is not the original behavior and can't be
+	 * changed until users trained themselves not to type
+	 * "git add -u" or "git add -A". For now, we warn and
+	 * keep the old behavior. Later, the behavior can be changed
+	 * to tree-wide, keeping the warning for a while, and
+	 * eventually we can drop the warning.
+	 */
+	warning(_("The behavior of 'git add %s (or %s)' with no path argument from a\n"
+		  "subdirectory of the tree will change in Git 2.0 and should not be used anymore.\n"
+		  "To add content for the whole tree, run:\n"
+		  "\n"
+		  "  git add %s :/\n"
+		  "  (or git add %s :/)\n"
+		  "\n"
+		  "To restrict the command to the current directory, run:\n"
+		  "\n"
+		  "  git add %s .\n"
+		  "  (or git add %s .)\n"
+		  "\n"
+		  "With the current Git version, the command is restricted to "
+		  "the current directory.\n"
+		  ""),
+		option_with_implicit_dot, short_option_with_implicit_dot,
+		option_with_implicit_dot, short_option_with_implicit_dot,
+		option_with_implicit_dot, short_option_with_implicit_dot);
+}
+
 static int fix_unmerged_status(struct diff_filepair *p,
 			       struct update_callback_data *data)
 {
@@ -54,10 +98,26 @@ static void update_callback(struct diff_queue_struct *q,
 {
 	int i;
 	struct update_callback_data *data = cbdata;
+	const char *implicit_dot = data->implicit_dot;
+	size_t implicit_dot_len = data->implicit_dot_len;
 
 	for (i = 0; i < q->nr; i++) {
 		struct diff_filepair *p = q->queue[i];
 		const char *path = p->one->path;
+		/*
+		 * Check if "git add -A" or "git add -u" was run from a
+		 * subdirectory with a modified file outside that directory,
+		 * and warn if so.
+		 *
+		 * "git add -u" will behave like "git add -u :/" instead of
+		 * "git add -u ." in the future.  This warning prepares for
+		 * that change.
+		 */
+		if (implicit_dot &&
+		    strncmp_icase(path, implicit_dot, implicit_dot_len)) {
+			warn_pathless_add();
+			continue;
+		}
 		switch (fix_unmerged_status(p, data)) {
 		default:
 			die(_("unexpected diff status %c"), p->status);
@@ -85,20 +145,34 @@ int add_files_to_cache(const char *prefix, const char **pathspec, int flags)
 {
 	struct update_callback_data data;
 	struct rev_info rev;
+
+	memset(&data, 0, sizeof(data));
+	data.flags = flags & ~ADD_CACHE_IMPLICIT_DOT;
+	if ((flags & ADD_CACHE_IMPLICIT_DOT) && prefix) {
+		/*
+		 * Check for modified files throughout the worktree so
+		 * update_callback has a chance to warn about changes
+		 * outside the cwd.
+		 */
+		data.implicit_dot = prefix;
+		data.implicit_dot_len = strlen(prefix);
+		pathspec = NULL;
+	}
+
 	init_revisions(&rev, prefix);
 	setup_revisions(0, NULL, &rev, NULL);
 	init_pathspec(&rev.prune_data, pathspec);
 	rev.diffopt.output_format = DIFF_FORMAT_CALLBACK;
 	rev.diffopt.format_callback = update_callback;
-	data.flags = flags;
-	data.add_errors = 0;
 	rev.diffopt.format_callback_data = &data;
 	rev.max_count = 0; /* do not compare unmerged paths with stage #2 */
 	run_diff_files(&rev, DIFF_RACY_IS_MODIFIED);
 	return !!data.add_errors;
 }
 
-static char *prune_directory(struct dir_struct *dir, const char **pathspec, int prefix)
+#define WARN_IMPLICIT_DOT (1u << 0)
+static char *prune_directory(struct dir_struct *dir, const char **pathspec,
+			     int prefix, unsigned flag)
 {
 	char *seen;
 	int i, specs;
@@ -115,6 +189,16 @@ static char *prune_directory(struct dir_struct *dir, const char **pathspec, int
 		if (match_pathspec(pathspec, entry->name, entry->len,
 				   prefix, seen))
 			*dst++ = entry;
+		else if (flag & WARN_IMPLICIT_DOT)
+			/*
+			 * "git add -A" was run from a subdirectory with a
+			 * new file outside that directory.
+			 *
+			 * "git add -A" will behave like "git add -A :/"
+			 * instead of "git add -A ." in the future.
+			 * Warn about the coming behavior change.
+			 */
+			warn_pathless_add();
 	}
 	dir->nr = dst - dir->entries;
 	add_pathspec_matches_against_index(pathspec, seen, specs);
@@ -321,35 +405,6 @@ static int add_files(struct dir_struct *dir, int flags)
 	return exit_status;
 }
 
-static void warn_pathless_add(const char *option_name, const char *short_name) {
-	/*
-	 * To be consistent with "git add -p" and most Git
-	 * commands, we should default to being tree-wide, but
-	 * this is not the original behavior and can't be
-	 * changed until users trained themselves not to type
-	 * "git add -u" or "git add -A". For now, we warn and
-	 * keep the old behavior. Later, the behavior can be changed
-	 * to tree-wide, keeping the warning for a while, and
-	 * eventually we can drop the warning.
-	 */
-	warning(_("The behavior of 'git add %s (or %s)' with no path argument from a\n"
-		  "subdirectory of the tree will change in Git 2.0 and should not be used anymore.\n"
-		  "To add content for the whole tree, run:\n"
-		  "\n"
-		  "  git add %s :/\n"
-		  "  (or git add %s :/)\n"
-		  "\n"
-		  "To restrict the command to the current directory, run:\n"
-		  "\n"
-		  "  git add %s .\n"
-		  "  (or git add %s .)\n"
-		  "\n"
-		  "With the current Git version, the command is restricted to the current directory."),
-		option_name, short_name,
-		option_name, short_name,
-		option_name, short_name);
-}
-
 int cmd_add(int argc, const char **argv, const char *prefix)
 {
 	int exit_status = 0;
@@ -360,8 +415,7 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 	int add_new_files;
 	int require_pathspec;
 	char *seen = NULL;
-	const char *option_with_implicit_dot = NULL;
-	const char *short_option_with_implicit_dot = NULL;
+	int implicit_dot = 0;
 
 	git_config(add_config, NULL);
 
@@ -391,11 +445,9 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 	}
 	if (option_with_implicit_dot && !argc) {
 		static const char *here[2] = { ".", NULL };
-		if (prefix)
-			warn_pathless_add(option_with_implicit_dot,
-					  short_option_with_implicit_dot);
 		argc = 1;
 		argv = here;
+		implicit_dot = 1;
 	}
 
 	add_new_files = !take_worktree_changes && !refresh_only;
@@ -408,7 +460,8 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 		 (intent_to_add ? ADD_CACHE_INTENT : 0) |
 		 (ignore_add_errors ? ADD_CACHE_IGNORE_ERRORS : 0) |
 		 (!(addremove || take_worktree_changes)
-		  ? ADD_CACHE_IGNORE_REMOVAL : 0));
+		  ? ADD_CACHE_IGNORE_REMOVAL : 0)) |
+		 (implicit_dot ? ADD_CACHE_IMPLICIT_DOT : 0);
 
 	if (require_pathspec && argc == 0) {
 		fprintf(stderr, _("Nothing specified, nothing added.\n"));
@@ -432,9 +485,10 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 		}
 
 		/* This picks up the paths that are not tracked */
-		baselen = fill_directory(&dir, pathspec);
+		baselen = fill_directory(&dir, implicit_dot ? NULL : pathspec);
 		if (pathspec)
-			seen = prune_directory(&dir, pathspec, baselen);
+			seen = prune_directory(&dir, pathspec, baselen,
+					implicit_dot ? WARN_IMPLICIT_DOT : 0);
 	}
 
 	if (refresh_only) {

cache.h

@@ -465,6 +465,7 @@ extern int remove_file_from_index(struct index_state *, const char *path);
 #define ADD_CACHE_IGNORE_ERRORS	4
 #define ADD_CACHE_IGNORE_REMOVAL 8
 #define ADD_CACHE_INTENT 16
+#define ADD_CACHE_IMPLICIT_DOT 32	/* internal to "git add -u/-A" */
 extern int add_to_index(struct index_state *, const char *path, struct stat *, int flags);
 extern int add_file_to_index(struct index_state *, const char *path, int flags);
 extern struct cache_entry *make_cache_entry(unsigned int mode, const unsigned char *sha1, const char *path, int stage, int refresh);