+ /* Fix the length of the whole thing */
+ postimage->len = new - postimage->buf;
+}
+
+static int match_fragment(struct image *img,
+ struct image *preimage,
+ struct image *postimage,
+ unsigned long try,
+ int try_lno,
+ unsigned ws_rule,
+ int match_beginning, int match_end)
+{
+ int i;
+ char *fixed_buf, *buf, *orig, *target;
+
+ if (preimage->nr + try_lno > img->nr)
+ return 0;
+
+ if (match_beginning && try_lno)
+ return 0;
+
+ if (match_end && preimage->nr + try_lno != img->nr)
+ return 0;
+
+ /* Quick hash check */
+ for (i = 0; i < preimage->nr; i++)
+ if (preimage->line[i].hash != img->line[try_lno + i].hash)
+ return 0;
+
+ /*
+ * Do we have an exact match? If we were told to match
+ * at the end, size must be exactly at try+fragsize,
+ * otherwise try+fragsize must be still within the preimage,
+ * and either case, the old piece should match the preimage
+ * exactly.
+ */
+ if ((match_end
+ ? (try + preimage->len == img->len)
+ : (try + preimage->len <= img->len)) &&
+ !memcmp(img->buf + try, preimage->buf, preimage->len))
+ return 1;
+
+ if (ws_error_action != correct_ws_error)
+ return 0;
+
+ /*
+ * The hunk does not apply byte-by-byte, but the hash says
+ * it might with whitespace fuzz.
+ */
+ fixed_buf = xmalloc(preimage->len + 1);
+ buf = fixed_buf;
+ orig = preimage->buf;
+ target = img->buf + try;
+ for (i = 0; i < preimage->nr; i++) {
+ size_t fixlen; /* length after fixing the preimage */
+ size_t oldlen = preimage->line[i].len;
+ size_t tgtlen = img->line[try_lno + i].len;
+ size_t tgtfixlen; /* length after fixing the target line */
+ char tgtfixbuf[1024], *tgtfix;
+ int match;
+
+ /* Try fixing the line in the preimage */
+ fixlen = ws_fix_copy(buf, orig, oldlen, ws_rule, NULL);
+
+ /* Try fixing the line in the target */
+ if (sizeof(tgtfixbuf) < tgtlen)
+ tgtfix = tgtfixbuf;
+ else
+ tgtfix = xmalloc(tgtlen);
+ tgtfixlen = ws_fix_copy(tgtfix, target, tgtlen, ws_rule, NULL);
+
+ /*
+ * If they match, either the preimage was based on
+ * a version before our tree fixed whitespace breakage,
+ * or we are lacking a whitespace-fix patch the tree
+ * the preimage was based on already had (i.e. target
+ * has whitespace breakage, the preimage doesn't).
+ * In either case, we are fixing the whitespace breakages
+ * so we might as well take the fix together with their
+ * real change.
+ */
+ match = (tgtfixlen == fixlen && !memcmp(tgtfix, buf, fixlen));
+
+ if (tgtfix != tgtfixbuf)
+ free(tgtfix);
+ if (!match)
+ goto unmatch_exit;
+
+ orig += oldlen;
+ buf += fixlen;
+ target += tgtlen;
+ }
+
+ /*
+ * Yes, the preimage is based on an older version that still
+ * has whitespace breakages unfixed, and fixing them makes the
+ * hunk match. Update the context lines in the postimage.
+ */
+ update_pre_post_images(preimage, postimage,
+ fixed_buf, buf - fixed_buf);
+ return 1;
+
+ unmatch_exit:
+ free(fixed_buf);
+ return 0;
+}
+
+static int find_pos(struct image *img,
+ struct image *preimage,
+ struct image *postimage,
+ int line,
+ unsigned ws_rule,
+ int match_beginning, int match_end)
+{
+ int i;
+ unsigned long backwards, forwards, try;
+ int backwards_lno, forwards_lno, try_lno;
+
+ if (preimage->nr > img->nr)
+ return -1;
+
+ /*
+ * If match_begining or match_end is specified, there is no
+ * point starting from a wrong line that will never match and
+ * wander around and wait for a match at the specified end.
+ */
+ if (match_beginning)
+ line = 0;
+ else if (match_end)
+ line = img->nr - preimage->nr;
+
+ if (line > img->nr)
+ line = img->nr;
+
+ try = 0;
+ for (i = 0; i < line; i++)
+ try += img->line[i].len;