[PATCH] git-revert is one of the most misunderstood command in git, help users out.

[Pierre Habouzit <madcoder@debian.org>]

When git-revert has a file argument then redirect the user to what he
probably meant.

Signed-off-by: Pierre Habouzit <madcoder@debian.org>
---
 builtin-revert.c |   24 +++++++++++++++++-------
 gitk             |    2 +-
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/builtin-revert.c b/builtin-revert.c
index 62ab1fa..9660048 100644
--- a/builtin-revert.c
+++ b/builtin-revert.c
@@ -38,7 +38,7 @@ static const char *me;
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
-static void parse_args(int argc, const char **argv)
+static void parse_args(int argc, const char **argv, const char *prefix)
 {
 	const char * const * usage_str =
 		action == REVERT ?  revert_usage : cherry_pick_usage;
@@ -58,8 +58,18 @@ static void parse_args(int argc, const char **argv)
 		usage_with_options(usage_str, options);
 	arg = argv[0];
 
-	if (get_sha1(arg, sha1))
-		die ("Cannot find '%s'", arg);
+	if (get_sha1(arg, sha1)) {
+		struct stat st;
+		const char *name;
+
+		name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
+		if (!lstat(name, &st)) {
+			die("Cannot find commit '%s', did you meant: "
+				"git checkout HEAD -- '%s'", arg, arg);
+		} else {
+			die("Cannot find commit '%s'", arg);
+		}
+	}
 	commit = (struct commit *)parse_object(sha1);
 	if (!commit)
 		die ("Could not find %s", sha1_to_hex(sha1));
@@ -225,7 +235,7 @@ static int merge_recursive(const char *base_sha1,
 	return run_command_v_opt(argv, RUN_COMMAND_NO_STDIN | RUN_GIT_CMD);
 }
 
-static int revert_or_cherry_pick(int argc, const char **argv)
+static int revert_or_cherry_pick(int argc, const char **argv, const char *prefix)
 {
 	unsigned char head[20];
 	struct commit *base, *next, *parent;
@@ -237,7 +247,7 @@ static int revert_or_cherry_pick(int argc, const char **argv)
 	git_config(git_default_config);
 	me = action == REVERT ? "revert" : "cherry-pick";
 	setenv(GIT_REFLOG_ACTION, me, 0);
-	parse_args(argc, argv);
+	parse_args(argc, argv, prefix);
 
 	/* this is copied from the shell script, but it's never triggered... */
 	if (action == REVERT && !no_replay)
@@ -405,12 +415,12 @@ int cmd_revert(int argc, const char **argv, const char *prefix)
 		edit = 1;
 	no_replay = 1;
 	action = REVERT;
-	return revert_or_cherry_pick(argc, argv);
+	return revert_or_cherry_pick(argc, argv, prefix);
 }
 
 int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
 {
 	no_replay = 0;
 	action = CHERRY_PICK;
-	return revert_or_cherry_pick(argc, argv);
+	return revert_or_cherry_pick(argc, argv, prefix);
 }
diff --git a/gitk b/gitk
index 1da0b0a..ab8bab2 100755
--- a/gitk
+++ b/gitk
@@ -1,6 +1,6 @@
 #!/bin/sh
 # Tcl ignores the next line -*- tcl -*- \
-exec wish "$0" -- "$@"
+exec wish8.5 "$0" -- "$@"
 
 # Copyright (C) 2005-2006 Paul Mackerras.  All rights reserved.
 # This program is free software; it may be used, copied, modified
-- 
1.5.3.5.1541.gd2b5c-dirty