+static int line_by_line_fuzzy_match(struct image *img,
+ struct image *preimage,
+ struct image *postimage,
+ unsigned long try,
+ int try_lno,
+ int preimage_limit)
+{
+ int i;
+ size_t imgoff = 0;
+ size_t preoff = 0;
+ size_t postlen = postimage->len;
+ size_t extra_chars;
+ char *buf;
+ char *preimage_eof;
+ char *preimage_end;
+ struct strbuf fixed;
+ char *fixed_buf;
+ size_t fixed_len;
+
+ for (i = 0; i < preimage_limit; i++) {
+ size_t prelen = preimage->line[i].len;
+ size_t imglen = img->line[try_lno+i].len;
+
+ if (!fuzzy_matchlines(img->buf + try + imgoff, imglen,
+ preimage->buf + preoff, prelen))
+ return 0;
+ if (preimage->line[i].flag & LINE_COMMON)
+ postlen += imglen - prelen;
+ imgoff += imglen;
+ preoff += prelen;
+ }
+
+ /*
+ * Ok, the preimage matches with whitespace fuzz.
+ *
+ * imgoff now holds the true length of the target that
+ * matches the preimage before the end of the file.
+ *
+ * Count the number of characters in the preimage that fall
+ * beyond the end of the file and make sure that all of them
+ * are whitespace characters. (This can only happen if
+ * we are removing blank lines at the end of the file.)
+ */
+ buf = preimage_eof = preimage->buf + preoff;
+ for ( ; i < preimage->nr; i++)
+ preoff += preimage->line[i].len;
+ preimage_end = preimage->buf + preoff;
+ for ( ; buf < preimage_end; buf++)
+ if (!isspace(*buf))
+ return 0;
+
+ /*
+ * Update the preimage and the common postimage context
+ * lines to use the same whitespace as the target.
+ * If whitespace is missing in the target (i.e.
+ * if the preimage extends beyond the end of the file),
+ * use the whitespace from the preimage.
+ */
+ extra_chars = preimage_end - preimage_eof;
+ strbuf_init(&fixed, imgoff + extra_chars);
+ strbuf_add(&fixed, img->buf + try, imgoff);
+ strbuf_add(&fixed, preimage_eof, extra_chars);
+ fixed_buf = strbuf_detach(&fixed, &fixed_len);
+ update_pre_post_images(preimage, postimage,
+ fixed_buf, fixed_len, postlen);
+ return 1;
+}
+