commit: detect misspelled pathspec while making a partial commit.

When you say "git commit Documentaiton" to make partial commit
for the files only in that directory, we did not detect that as
a misspelled pathname and attempted to commit index without
change.  If nothing matched, there is no harm done, but if the
index gets modified otherwise by having another valid pathspec
or after an explicit update-index, a user will not notice
without paying attention to the "git status" preview.

This introduces --error-unmatch option to ls-files, and uses it
to detect this common user error.

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

1 files changed, 44 insertions, 7 deletions

diff --git a/ls-files.c b/ls-files.c
index 7024cf18e1..a716e5fad2 100644
--- a/ls-files.c
+++ b/ls-files.c
@@ -25,6 +25,8 @@ static int line_terminator = '\n';
 static int prefix_len = 0, prefix_offset = 0;
 static const char *prefix = NULL;
 static const char **pathspec = NULL;
+static int error_unmatch = 0;
+static char *ps_matched = NULL;
 
 static const char *tag_cached = "";
 static const char *tag_unmerged = "";
@@ -325,7 +327,8 @@ static int cmp_name(const void *p1, const void *p2)
  * Match a pathspec against a filename. The first "len" characters
  * are the common prefix
  */
-static int match(const char **spec, const char *filename, int len)
+static int match(const char **spec, char *ps_matched,
+		 const char *filename, int len)
 {
 	const char *m;
 
@@ -333,17 +336,24 @@ static int match(const char **spec, const char *filename, int len)
 		int matchlen = strlen(m + len);
 
 		if (!matchlen)
-			return 1;
+			goto matched;
 		if (!strncmp(m + len, filename + len, matchlen)) {
 			if (m[len + matchlen - 1] == '/')
-				return 1;
+				goto matched;
 			switch (filename[len + matchlen]) {
 			case '/': case '\0':
-				return 1;
+				goto matched;
 			}
 		}
 		if (!fnmatch(m + len, filename + len, 0))
-			return 1;
+			goto matched;
+		if (ps_matched)
+			ps_matched++;
+		continue;
+	matched:
+		if (ps_matched)
+			*ps_matched = 1;
+		return 1;
 	}
 	return 0;
 }
@@ -356,7 +366,7 @@ static void show_dir_entry(const char *tag, struct nond_on_fs *ent)
 	if (len >= ent->len)
 		die("git-ls-files: internal error - directory entry not superset of prefix");
 
-	if (pathspec && !match(pathspec, ent->name, len))
+	if (pathspec && !match(pathspec, ps_matched, ent->name, len))
 		return;
 
 	fputs(tag, stdout);
@@ -444,7 +454,7 @@ static void show_ce_entry(const char *tag, struct cache_entry *ce)
 	if (len >= ce_namelen(ce))
 		die("git-ls-files: internal error - cache entry not superset of prefix");
 
-	if (pathspec && !match(pathspec, ce->name, len))
+	if (pathspec && !match(pathspec, ps_matched, ce->name, len))
 		return;
 
 	if (!show_stage) {
@@ -699,6 +709,10 @@ int main(int argc, const char **argv)
 			prefix_offset = 0;
 			continue;
 		}
+		if (!strcmp(arg, "--error-unmatch")) {
+			error_unmatch = 1;
+			continue;
+		}
 		if (*arg == '-')
 			usage(ls_files_usage);
 		break;
@@ -710,6 +724,14 @@ int main(int argc, const char **argv)
 	if (pathspec)
 		verify_pathspec();
 
+	/* Treat unmatching pathspec elements as errors */
+	if (pathspec && error_unmatch) {
+		int num;
+		for (num = 0; pathspec[num]; num++)
+			;
+		ps_matched = xcalloc(1, num);
+	}
+
 	if (show_ignored && !exc_given) {
 		fprintf(stderr, "%s: --ignored needs some exclude pattern\n",
 			argv[0]);
@@ -725,5 +747,20 @@ int main(int argc, const char **argv)
 	if (prefix)
 		prune_cache();
 	show_files();
+
+	if (ps_matched) {
+		/* We need to make sure all pathspec matched otherwise
+		 * it is an error.
+		 */
+		int num, errors = 0;
+		for (num = 0; pathspec[num]; num++) {
+			if (ps_matched[num])
+				continue;
+			error("pathspec '%s' did not match any.",
+			      pathspec[num] + prefix_len);
+		}
+		return errors ? 1 : 0;
+	}
+
 	return 0;
 }