revision parsing: make "rev -- paths" checks stronger.

If you don't have a "--" marker, then:

 - all of the arguments we are going to assume are pathspecs
   must exist in the working tree.

 - none of the arguments we parsed as revisions could be
   interpreted as a filename.

so that there really isn't any possibility of confusion in case
somebody does have a revision that looks like a pathname too.

The former rule has been in effect; this implements the latter.

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 22 insertions, 2 deletions

diff --git a/setup.c b/setup.c
index cce9bb806..fe7f88469 100644
--- a/setup.c
+++ b/setup.c
@@ -80,11 +80,31 @@ void verify_filename(const char *prefix, const char *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("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
+		    "Use '--' to separate paths from revisions", arg);
 	die("'%s': %s", arg, strerror(errno));
 }
 
+/*
+ * Opposite of the above: the command line did not have -- marker
+ * and we parsed the arg as a refname.  It should not be interpretable
+ * as a filename.
+ */
+void verify_non_filename(const char *prefix, const char *arg)
+{
+	const char *name;
+	struct stat st;
+
+	if (*arg == '-')
+		return; /* flag */
+	name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
+	if (!lstat(name, &st))
+		die("ambiguous argument '%s': both revision and filename\n"
+		    "Use '--' to separate filenames from revisions", arg);
+	if (errno != ENOENT)
+		die("'%s': %s", arg, strerror(errno));
+}
+
 const char **get_pathspec(const char *prefix, const char **pathspec)
 {
 	const char *entry = *pathspec;