diff --stat: ensure at least one '-' for deletions, and one '+' for additions

diff --git a/diff.c b/diff.c
index 3fd7a5220d283ef0e575cfb0d436c029977c632e..2df085f3c67afd96b5fcea5ade6f45c5e330198b 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -550,9 +550,12 @@ const char mime_boundary_leader[] = "------------";
 static int scale_linear(int it, int width, int max_change)
 {
        /*
-        * round(width * it / max_change);
+        * make sure that at least one '-' is printed if there were deletions,
+        * and likewise for '+'.
         */
-       return (it * width * 2 + max_change) / (max_change * 2);
+       if (max_change < 2)
+               return it;
+       return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
 }
 
 static void show_name(const char *prefix, const char *name, int len,
@@ -684,9 +687,9 @@ static void show_stats(struct diffstat_t* data, struct diff_options *options)
                dels += del;
 
                if (width <= max_change) {
-                       total = scale_linear(total, width, max_change);
                        add = scale_linear(add, width, max_change);
-                       del = total - add;
+                       del = scale_linear(del, width, max_change);
+                       total = add + del;
                }
                show_name(prefix, name, len, reset, set);
                printf("%5d ", added + deleted);
@@ -1735,15 +1738,32 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
        else if (!strcmp(arg, "--patch-with-raw")) {
                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
        }
-       else if (!strcmp(arg, "--stat"))
-               options->output_format |= DIFF_FORMAT_DIFFSTAT;
-       else if (!strncmp(arg, "--stat-width=", 13)) {
-               options->stat_width = strtoul(arg + 13, NULL, 10);
-               options->output_format |= DIFF_FORMAT_DIFFSTAT;
-       }
-       else if (!strncmp(arg, "--stat-name-width=", 18)) {
-               options->stat_name_width = strtoul(arg + 18, NULL, 10);
+       else if (!strncmp(arg, "--stat", 6)) {
+               char *end;
+               int width = options->stat_width;
+               int name_width = options->stat_name_width;
+               arg += 6;
+               end = (char *)arg;
+
+               switch (*arg) {
+               case '-':
+                       if (!strncmp(arg, "-width=", 7))
+                               width = strtoul(arg + 7, &end, 10);
+                       else if (!strncmp(arg, "-name-width=", 12))
+                               name_width = strtoul(arg + 12, &end, 10);
+                       break;
+               case '=':
+                       width = strtoul(arg+1, &end, 10);
+                       if (*end == ',')
+                               name_width = strtoul(end+1, &end, 10);
+               }
+
+               /* Important! This checks all the error cases! */
+               if (*end)
+                       return 0;
                options->output_format |= DIFF_FORMAT_DIFFSTAT;
+               options->stat_name_width = name_width;
+               options->stat_width = width;
        }
        else if (!strcmp(arg, "--check"))
                options->output_format |= DIFF_FORMAT_CHECKDIFF;