git-pickaxe: allow "-L <something>,+N"

With this,

	git pickaxe -L '/--progress/,+20' v1.4.0 -- pack-objects.c

gives you 20 lines starting from the first occurrence of
'--progress' in pack-objects, digging from v1.4.0 version.

You can also say

	git pickaxe -L '/--progress/,-5' v1.4.0 -- pack-objects.c

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/builtin-pickaxe.c b/builtin-pickaxe.c
index 673185f96de4430a363b961bc9ab8912444808a1..64999f3577294eb2bfe030be386dacd7b3787bbf 100644 (file)
--- a/builtin-pickaxe.c
+++ b/builtin-pickaxe.c
@@ -1545,6 +1545,25 @@ static const char *parse_loc(const char *spec,
        regex_t regexp;
        regmatch_t match[1];
 
+       /* Allow "-L <something>,+20" to mean starting at <something>
+        * for 20 lines, or "-L <something>,-5" for 5 lines ending at
+        * <something>.
+        */
+       if (1 < begin && (spec[0] == '+' || spec[0] == '-')) {
+               num = strtol(spec + 1, &term, 10);
+               if (term != spec + 1) {
+                       if (spec[0] == '-')
+                               num = 0 - num;
+                       if (0 < num)
+                               *ret = begin + num - 2;
+                       else if (!num)
+                               *ret = begin;
+                       else
+                               *ret = begin + num;
+                       return term;
+               }
+               return spec;
+       }
        num = strtol(spec, &term, 10);
        if (term != spec) {
                *ret = num;