symbolic-ref --short: abbreviate the output unambiguously

diff --git a/diff.c b/diff.c
index 3550c18e390cac7a3cce8fcf93074c7178bf1994..a1c06b554b80e433dcb735c8e0adf186b6252ae5 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -1273,13 +1273,15 @@ const char mime_boundary_leader[] = "------------";
 
 static int scale_linear(int it, int width, int max_change)
 {
+       if (!it)
+               return 0;
        /*
-        * make sure that at least one '-' is printed if there were deletions,
-        * and likewise for '+'.
+        * make sure that at least one '-' or '+' is printed if
+        * there is any change to this path. The easiest way is to
+        * scale linearly as if the alloted width is one column shorter
+        * than it is, and then add 1 to the result.
         */
-       if (max_change < 2)
-               return it;
-       return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
+       return 1 + (it * (width - 1) / max_change);
 }
 
 static void show_name(FILE *file,
@@ -1495,8 +1497,19 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
                dels += del;
 
                if (width <= max_change) {
-                       add = scale_linear(add, width, max_change);
-                       del = scale_linear(del, width, max_change);
+                       int total = add + del;
+
+                       total = scale_linear(add + del, width, max_change);
+                       if (total < 2 && add && del)
+                               /* width >= 2 due to the sanity check */
+                               total = 2;
+                       if (add < del) {
+                               add = scale_linear(add, width, max_change);
+                               del = total - add;
+                       } else {
+                               del = scale_linear(del, width, max_change);
+                               add = total - del;
+                       }
                }
                fprintf(options->file, "%s", line_prefix);
                show_name(options->file, prefix, name, len);