print errno when reporting a system call error

diff --git a/diff-no-index.c b/diff-no-index.c
index df762fd0f7d1ec74175a42de07b064107d3a601a..79229382b06cefc98aa8926065f0fb999ad1da2e 100644 (file)
--- a/diff-no-index.c
+++ b/diff-no-index.c
@@ -236,7 +236,7 @@ static void fixup_paths(const char **path, struct strbuf *replacement)
 void diff_no_index(struct rev_info *revs,
                   int argc, const char **argv)
 {
-       int i, prefixlen;
+       int i;
        const char *paths[2];
        struct strbuf replacement = STRBUF_INIT;
        const char *prefix = revs->prefix;
@@ -257,7 +257,6 @@ void diff_no_index(struct rev_info *revs,
                }
        }
 
-       prefixlen = prefix ? strlen(prefix) : 0;
        for (i = 0; i < 2; i++) {
                const char *p = argv[argc - 2 + i];
                if (!strcmp(p, "-"))
@@ -266,8 +265,8 @@ void diff_no_index(struct rev_info *revs,
                         * path that is "-", spell it as "./-".
                         */
                        p = file_from_standard_input;
-               else if (prefixlen)
-                       p = xstrdup(prefix_filename(prefix, prefixlen, p));
+               else if (prefix)
+                       p = prefix_filename(prefix, p);
                paths[i] = p;
        }