reset: make the reminder output consistent with "checkout"

git reset without argument displays a summary of the local modification,
like this:

    $ git reset
    Makefile: locally modified

Some people have problems with this; they look like an error message.

This patch makes its output mimic how "git checkout $another_branch"
reports the paths with local modifications.  "git add --refresh --verbose"
is changed in the same way.

It also adds a header to make it clear that the output is informative,
and not an error.
Signed-off-by: NMatthieu Moy <Matthieu.Moy@imag.fr>

builtin-add.c

@@ -106,7 +106,7 @@ static void refresh(int verbose, const char **pathspec)
 		/* nothing */;
 	seen = xcalloc(specs, 1);
 	refresh_index(&the_index, verbose ? REFRESH_IN_PORCELAIN : REFRESH_QUIET,
-		      pathspec, seen);
+		      pathspec, seen, "Unstaged changes after refreshing the index:");
 	for (i = 0; i < specs; i++) {
 		if (!seen[i])
 			die("pathspec '%s' did not match any files", pathspec[i]);

builtin-reset.c

@@ -108,7 +108,8 @@ static int update_index_refresh(int fd, struct lock_file *index_lock, int flags)
 	if (read_cache() < 0)
 		return error("Could not read index");
 
-	result = refresh_cache(flags) ? 1 : 0;
+	result = refresh_index(&the_index, (flags), NULL, NULL,
+			       "Unstaged changes after reset:") ? 1 : 0;
 	if (write_cache(fd, active_cache, active_nr) ||
 			commit_locked_index(index_lock))
 		return error ("Could not refresh index");

cache.h

@@ -330,7 +330,7 @@ static inline void remove_name_hash(struct cache_entry *ce)
 #define remove_file_from_cache(path) remove_file_from_index(&the_index, (path))
 #define add_to_cache(path, st, flags) add_to_index(&the_index, (path), (st), (flags))
 #define add_file_to_cache(path, flags) add_file_to_index(&the_index, (path), (flags))
-#define refresh_cache(flags) refresh_index(&the_index, (flags), NULL, NULL)
+#define refresh_cache(flags) refresh_index(&the_index, (flags), NULL, NULL, NULL)
 #define ce_match_stat(ce, st, options) ie_match_stat(&the_index, (ce), (st), (options))
 #define ce_modified(ce, st, options) ie_modified(&the_index, (ce), (st), (options))
 #define cache_name_exists(name, namelen, igncase) index_name_exists(&the_index, (name), (namelen), (igncase))
@@ -477,7 +477,7 @@ extern int check_path(const char *path, int len, struct stat *st);
 #define REFRESH_IGNORE_MISSING	0x0008	/* ignore non-existent */
 #define REFRESH_IGNORE_SUBMODULES	0x0010	/* ignore submodules */
 #define REFRESH_IN_PORCELAIN	0x0020	/* user friendly output, not "needs update" */
-extern int refresh_index(struct index_state *, unsigned int flags, const char **pathspec, char *seen);
+extern int refresh_index(struct index_state *, unsigned int flags, const char **pathspec, char *seen, char *header_msg);
 
 struct lock_file {
 	struct lock_file *next;

read-cache.c

@@ -1065,7 +1065,18 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
 	return updated;
 }
 
-int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen)
+static void show_file(const char * fmt, const char * name, int in_porcelain,
+		      int * first, char *header_msg)
+{
+	if (in_porcelain && *first && header_msg) {
+		printf("%s\n", header_msg);
+		*first=0;
+	}
+	printf(fmt, name);
+}
+
+int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec,
+		  char *seen, char *header_msg)
 {
 	int i;
 	int has_errors = 0;
@@ -1074,11 +1085,14 @@ int refresh_index(struct index_state *istate, unsigned int flags, const char **p
 	int quiet = (flags & REFRESH_QUIET) != 0;
 	int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
 	int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0;
+	int first = 1;
+	int in_porcelain = (flags & REFRESH_IN_PORCELAIN);
 	unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
-	const char *needs_update_message;
+	const char *needs_update_fmt;
+	const char *needs_merge_fmt;
 
-	needs_update_message = ((flags & REFRESH_IN_PORCELAIN)
-				? "locally modified" : "needs update");
+	needs_update_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n");
+	needs_merge_fmt = (in_porcelain ? "U\t%s\n" : "%s: needs merge\n");
 	for (i = 0; i < istate->cache_nr; i++) {
 		struct cache_entry *ce, *new;
 		int cache_errno = 0;
@@ -1094,7 +1108,7 @@ int refresh_index(struct index_state *istate, unsigned int flags, const char **p
 			i--;
 			if (allow_unmerged)
 				continue;
-			printf("%s: needs merge\n", ce->name);
+			show_file(needs_merge_fmt, ce->name, in_porcelain, &first, header_msg);
 			has_errors = 1;
 			continue;
 		}
@@ -1117,7 +1131,7 @@ int refresh_index(struct index_state *istate, unsigned int flags, const char **p
 			}
 			if (quiet)
 				continue;
-			printf("%s: %s\n", ce->name, needs_update_message);
+			show_file(needs_update_fmt, ce->name, in_porcelain, &first, header_msg);
 			has_errors = 1;
 			continue;
 		}

t/t7102-reset.sh

@@ -419,7 +419,8 @@ test_expect_success 'resetting an unmodified path is a no-op' '
 '
 
 cat > expect << EOF
-file2: locally modified
+Unstaged changes after reset:
+M	file2
 EOF
 
 test_expect_success '--mixed refreshes the index' '