git-apply: fix whitespace stripping

The algorithm isn't right here: it accumulates any set of 8 spaces into
tabs even if they're separated by tabs, so

	<four spaces><tab><four spaces><tab>

is converted to

	<tab><tab><tab>

when it should be just

	<tab><tab>

So teach git-apply that a tab hides any group of less than 8 previous
spaces in a row.

Signed-off-by: J. Bruce Fields <redacted>
Signed-off-by: Junio C Hamano <redacted>

diff --git a/builtin-apply.c b/builtin-apply.c
index f4ecf03ed465c942a395f4de5ca3ce17bbdd3011..5ad371424b8019a97d1fb34045bb8e32134870aa 100644 (file)
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@ -1642,15 +1642,22 @@ static int apply_line(char *output, const char *patch, int plen)
 
        buf = output;
        if (need_fix_leading_space) {
+               int consecutive_spaces = 0;
                /* between patch[1..last_tab_in_indent] strip the
                 * funny spaces, updating them to tab as needed.
                 */
                for (i = 1; i < last_tab_in_indent; i++, plen--) {
                        char ch = patch[i];
-                       if (ch != ' ')
+                       if (ch != ' ') {
+                               consecutive_spaces = 0;
                                *output++ = ch;
-                       else if ((i % 8) == 0)
-                               *output++ = '\t';
+                       } else {
+                               consecutive_spaces++;
+                               if (consecutive_spaces == 8) {
+                                       *output++ = '\t';
+                                       consecutive_spaces = 0;
+                               }
+                       }
                }
                fixed = 1;
                i = last_tab_in_indent;