ui-diff: show /dev/null as filename for add/delete

The diff headers showed an invalid filename when a patch created or
deleted a file. Fix it.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/ui-diff.c b/ui-diff.c
index 7ec5701..999b6f3 100644
--- a/ui-diff.c
+++ b/ui-diff.c
@@ -6,65 +6,68 @@
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 
 
 /*
  * print a single line returned from xdiff
  */
 static void print_line(char *line, int len)
 {
 	char *class = "ctx";
 	char c = line[len-1];
 
 	if (line[0] == '+')
 		class = "add";
 	else if (line[0] == '-')
 		class = "del";
 	else if (line[0] == '@')
 		class = "hunk";
 
 	htmlf("<div class='%s'>", class);
 	line[len-1] = '\0';
 	html_txt(line);
 	html("</div>");
 	line[len-1] = c;
 }
 
 static void header(unsigned char *sha1, char *path1,
 		   unsigned char *sha2, char *path2)
 {
 	char *abbrev1, *abbrev2;
-
+	if (is_null_sha1(sha1))
+		path1 = "dev/null";
+	if (is_null_sha1(sha2))
+		path2 = "dev/null";
 	html("<tr><td>");
 	html("<div class='head'>");
 	html("diff --git a/");
 	html_txt(path1);
 	html(" b/");
 	html_txt(path2);
 	abbrev1 = xstrdup(find_unique_abbrev(sha1, DEFAULT_ABBREV));
 	abbrev2 = xstrdup(find_unique_abbrev(sha2, DEFAULT_ABBREV));
 	htmlf("\nindex %s..%s", abbrev1, abbrev2);
 	free(abbrev1);
 	free(abbrev2);
 	html("\n--- a/");
 	html_txt(path1);
 	html("\n+++ b/");
 	html_txt(path2);
 	html("</div>");
 }
 
 static void filepair_cb(struct diff_filepair *pair)
 {
 	header(pair->one->sha1, pair->one->path,
 	       pair->two->sha1, pair->two->path);
 	if (cgit_diff_files(pair->one->sha1, pair->two->sha1, print_line))
 		cgit_print_error("Error running diff");
 	html("</tr></td>");
 }
 
 void cgit_print_diff(const char *old_hex, const char *new_hex, char *path)
 {
 	unsigned char sha1[20], sha2[20];
 	enum object_type type;
 	unsigned long size;