send-email: quiet some warnings, reject invalid addresses

[git.git] / diff.c

diff --git a/diff.c b/diff.c
index 7a7b839..5285c03 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -232,11 +232,16 @@ static char *pprint_rename(const char *a, const char *b)
         * name-a => name-b
         */
        if (pfx_length + sfx_length) {
+               int a_midlen = len_a - pfx_length - sfx_length;
+               int b_midlen = len_b - pfx_length - sfx_length;
+               if (a_midlen < 0) a_midlen = 0;
+               if (b_midlen < 0) b_midlen = 0;
+
                name = xmalloc(len_a + len_b - pfx_length - sfx_length + 7);
                sprintf(name, "%.*s{%.*s => %.*s}%s",
                        pfx_length, a,
-                       len_a - pfx_length - sfx_length, a + pfx_length,
-                       len_b - pfx_length - sfx_length, b + pfx_length,
+                       a_midlen, a + pfx_length,
+                       b_midlen, b + pfx_length,
                        a + len_a - sfx_length);
        }
        else {