Fix filename verification when in a subdirectory

When we are in a subdirectory of a git archive, we need to take the prefix
of that subdirectory into accoung when we verify filename arguments.

Noted by Matthias Lederhofer

This also uses the improved error reporting for all the other git commands
that use the revision parsing interfaces, not just git-rev-parse. Also, it
makes the error reporting for mixed filenames and argument flags clearer
(you cannot put flags after the start of the pathname list).

[jc: with fix to a trivial typo noticed by Timo Hirvonen]

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

4 files changed, 29 insertions, 18 deletions

diff --git a/cache.h b/cache.h
index 69801b02d5..4d8fabc6d8 100644
--- a/cache.h
+++ b/cache.h
@@ -134,6 +134,7 @@ extern const char *setup_git_directory_gently(int *);
 extern const char *setup_git_directory(void);
 extern const char *prefix_path(const char *prefix, int len, const char *path);
 extern const char *prefix_filename(const char *prefix, int len, const char *path);
+extern void verify_filename(const char *prefix, const char *name);
 
 #define alloc_nr(x) (((x)+16)*3/2)
 
diff --git a/rev-parse.c b/rev-parse.c
index 7f66ae2db8..62e16af33c 100644
--- a/rev-parse.c
+++ b/rev-parse.c
@@ -160,14 +160,6 @@ static int show_file(const char *arg)
 	return 0;
 }
 
-static void die_badfile(const char *arg)
-{
-	if (errno != ENOENT)
-		die("'%s': %s", arg, strerror(errno));
-	die("'%s' is ambiguous - revision name or file/directory name?\n"
-	    "Please put '--' before the list of filenames.", arg);
-}
-
 int main(int argc, char **argv)
 {
 	int i, as_is = 0, verify = 0;
@@ -177,14 +169,12 @@ int main(int argc, char **argv)
 	git_config(git_default_config);
 
 	for (i = 1; i < argc; i++) {
-		struct stat st;
 		char *arg = argv[i];
 		char *dotdot;
 
 		if (as_is) {
 			if (show_file(arg) && as_is < 2)
-				if (lstat(arg, &st) < 0)
-					die_badfile(arg);
+				verify_filename(prefix, arg);
 			continue;
 		}
 		if (!strcmp(arg,"-n")) {
@@ -350,8 +340,7 @@ int main(int argc, char **argv)
 			continue;
 		if (verify)
 			die("Needed a single revision");
-		if (lstat(arg, &st) < 0)
-			die_badfile(arg);
+		verify_filename(prefix, arg);
 	}
 	show_default();
 	if (verify && revs_count != 1)
diff --git a/revision.c b/revision.c
index e1f9816bd7..03dd238939 100644
--- a/revision.c
+++ b/revision.c
@@ -675,17 +675,15 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 			arg++;
 		}
 		if (get_sha1(arg, sha1) < 0) {
-			struct stat st;
 			int j;
 
 			if (seen_dashdash || local_flags)
 				die("bad revision '%s'", arg);
 
 			/* If we didn't have a "--", all filenames must exist */
-			for (j = i; j < argc; j++) {
-				if (lstat(argv[j], &st) < 0)
-					die("'%s': %s", argv[j], strerror(errno));
-			}
+			for (j = i; j < argc; j++)
+				verify_filename(revs->prefix, argv[j]);
+
 			revs->prune_data = get_pathspec(revs->prefix, argv + i);
 			break;
 		}
diff --git a/setup.c b/setup.c
index 36ede3d874..cce9bb8069 100644
--- a/setup.c
+++ b/setup.c
@@ -62,6 +62,29 @@ const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
 	return path;
 }
 
+/*
+ * Verify a filename that we got as an argument for a pathspec
+ * entry. Note that a filename that begins with "-" never verifies
+ * as true, because even if such a filename were to exist, we want
+ * it to be preceded by the "--" marker (or we want the user to
+ * use a format like "./-filename")
+ */
+void verify_filename(const char *prefix, const char *arg)
+{
+	const char *name;
+	struct stat st;
+
+	if (*arg == '-')
+		die("bad flag '%s' used after filename", arg);
+	name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
+	if (!lstat(name, &st))
+		return;
+	if (errno == ENOENT)
+		die("ambiguous argument '%s': unknown revision or filename\n"
+		    "Use '--' to separate filenames from revisions", arg);
+	die("'%s': %s", arg, strerror(errno));
+}
+
 const char **get_pathspec(const char *prefix, const char **pathspec)
 {
 	const char *entry = *pathspec;