Fix diff -B/--dirstat miscounting of newly added contents

What used to happen is that diffcore_count_changes() simply ignored any hashes in the destination that didn't match hashes in the source. EXCEPT if the source hash didn't exist at all, in which case it would count _one_ destination hash that happened to have the "next" hash value. As a consequence, newly added material was often undercounted, making output from --dirstat and "complete rewrite" detection used by -B unrelialble. This changes it so that: - whenever it bypasses a destination hash (because it doesn't match a source), it counts the bytes associated with that as "literal added" - at the end (once we have used up all the source hashes), we do the same thing with the remaining destination hashes. - when hashes do match, and we use the difference in counts as a value, we also use up that destination hash entry (the 'd++'). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Linus Torvalds committed Dec 4, 2009 at 12:07 UTC 77cd6ab62108c2d4ddd4343abd9bae17c406be4b

1 file changed +10 -1

diffcore-delta.c

+10 -1

@@ -201,10 +201,15 @@ int diffcore_count_changes(struct diff_filespec *src,

201 while (d->cnt) {

202 if (d->hashval >= s->hashval)

203 break;

204 + la += d->cnt;

205 d++;

206 }

207 src_cnt = s->cnt;

207 - dst_cnt = d->hashval == s->hashval ? d->cnt : 0;

208 + dst_cnt = 0;

209 + if (d->cnt && d->hashval == s->hashval) {

210 + dst_cnt = d->cnt;

211 + d++;

212 + }

213 if (src_cnt < dst_cnt) {

214 la += dst_cnt - src_cnt;

215 sc += src_cnt;

@@ -213,6 +218,10 @@ int diffcore_count_changes(struct diff_filespec *src,

218 sc += dst_cnt;

219 s++;

220 }

221 + while (d->cnt) {

222 + la += d->cnt;

223 + d++;

224 + }

225

226 if (!src_count_p)

227 free(src_count);