Mechanical conversion to use prefixcmp()

This mechanically converts strncmp() to use prefixcmp(), but only when
the parameters match specific patterns, so that they can be verified
easily.  Leftover from this will be fixed in a separate step, including
idiotic conversions like

    if (!strncmp("foo", arg, 3))

  =>

    if (!(-prefixcmp(arg, "foo")))

This was done by using this script in px.perl

   #!/usr/bin/perl -i.bak -p
   if (/strncmp\(([^,]+), "([^\\"]*)", (\d+)\)/ && (length($2) == $3)) {
           s|strncmp\(([^,]+), "([^\\"]*)", (\d+)\)|prefixcmp($1, "$2")|;
   }
   if (/strncmp\("([^\\"]*)", ([^,]+), (\d+)\)/ && (length($1) == $3)) {
           s|strncmp\("([^\\"]*)", ([^,]+), (\d+)\)|(-prefixcmp($2, "$1"))|;
   }

and running:

   $ git grep -l strncmp -- '*.c' | xargs perl px.perl

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

1 files changed, 6 insertions, 6 deletions

diff --git a/builtin-show-ref.c b/builtin-show-ref.c
index 853f13f6a..ae0edddac 100644
--- a/builtin-show-ref.c
+++ b/builtin-show-ref.c
@@ -28,8 +28,8 @@ static int show_ref(const char *refname, const unsigned char *sha1, int flag, vo
 	if (tags_only || heads_only) {
 		int match;
 
-		match = heads_only && !strncmp(refname, "refs/heads/", 11);
-		match |= tags_only && !strncmp(refname, "refs/tags/", 10);
+		match = heads_only && !prefixcmp(refname, "refs/heads/");
+		match |= tags_only && !prefixcmp(refname, "refs/tags/");
 		if (!match)
 			return 0;
 	}
@@ -178,8 +178,8 @@ int cmd_show_ref(int argc, const char **argv, const char *prefix)
 			hash_only = 1;
 			continue;
 		}
-		if (!strncmp(arg, "--hash=", 7) ||
-		    (!strncmp(arg, "--abbrev", 8) &&
+		if (!prefixcmp(arg, "--hash=") ||
+		    (!prefixcmp(arg, "--abbrev") &&
 		     (arg[8] == '=' || arg[8] == '\0'))) {
 			if (arg[2] != 'h' && !arg[8])
 				/* --abbrev only */
@@ -215,7 +215,7 @@ int cmd_show_ref(int argc, const char **argv, const char *prefix)
 		}
 		if (!strcmp(arg, "--exclude-existing"))
 			return exclude_existing(NULL);
-		if (!strncmp(arg, "--exclude-existing=", 19))
+		if (!prefixcmp(arg, "--exclude-existing="))
 			return exclude_existing(arg + 19);
 		usage(show_ref_usage);
 	}
@@ -224,7 +224,7 @@ int cmd_show_ref(int argc, const char **argv, const char *prefix)
 		unsigned char sha1[20];
 
 		while (*pattern) {
-			if (!strncmp(*pattern, "refs/", 5) &&
+			if (!prefixcmp(*pattern, "refs/") &&
 			    resolve_ref(*pattern, sha1, 1, NULL)) {
 				if (!quiet)
 					show_one(*pattern, sha1);