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Fixed bug with matching the end of a string #1

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Fixed bug with matching the end of a string #1

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db098a6
Update finediff.php
Jul 15, 2013
3845e4a
Update finediff.php
Jul 15, 2013
adedee7
Update finediff.php
Jul 17, 2013
052f4f7
Update README
Jul 17, 2013
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16 changes: 1 addition & 15 deletions README
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Original file line number Diff line number Diff line change
Expand Up @@ -73,21 +73,7 @@ FAQ
---

* Does it work with UTF-8?
As of now, the code assume single-byte characters. To use UTF-8 text, you can
always convert the encoding using mb_convert_encoding():
...
$from_text = mb_convert_encoding($from_text_utf8, 'HTML-ENTITIES', 'UTF-8');
$to_text = mb_convert_encoding($to_text_utf8, 'HTML-ENTITIES', 'UTF-8');
$diff_opcodes = FineDiff::getDiffOpcodes($from_text, $to_text);
...

If ever you want to re-generate the $to_text_utf8 from the $from_text_utf8:
...
$from_text = mb_convert_encoding($from_text_utf8, 'HTML-ENTITIES', 'UTF-8');
$to_text = FineDiff::renderToTextFromOpcodes($from_text, $diff_opcodes);
$to_text_utf8 = mb_convert_encoding($to_text, 'UTF-8', 'HTML-ENTITIES');
....

Yes!

License
-------
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23 changes: 19 additions & 4 deletions finediff.php
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Expand Up @@ -34,6 +34,10 @@
*
* 10-Dec-2011 (Christoph Mewes):
* - added UTF-8 support, fixed strange usage of htmlentities
*
* 15-Jul-2013 (Peter Bagnall):
* - fixed bug where getting the diff of "abc def" and "abc def ghi" would fail
* to recognise that def was a match, because whitespace was being included in fragments.
*/

mb_internal_encoding('UTF-8');
Expand Down Expand Up @@ -520,12 +524,17 @@ private static function doFragmentDiff($from_text, $to_text, $delimiters) {
$fragment_index_offset += $fragment_length;
}
if ( $fragment_index_offset > $best_copy_length ) {
$best_copy_length = $fragment_index_offset;
$best_from_start = $from_base_fragment_index;
$best_to_start = $to_base_fragment_index;
// if the matching string is just made up of delimiters then don't count it as a match. This prevents an
// excessive number of whitespaces being seen as matches and therefore breaking up a long replace segment
// to no useful purpose.
if ($fragment_index_offset > $from_base_fragment_length || self::mb_strspn($from_base_fragment, $delimiters, 0)===0) {
$best_copy_length = $fragment_index_offset;
$best_from_start = $from_base_fragment_index;
$best_to_start = $to_base_fragment_index;
}
}
}
$from_base_fragment_index += mb_strlen($from_base_fragment);
$from_base_fragment_index += $from_base_fragment_length;
// If match is larger than half segment size, no point trying to find better
// TODO: Really?
if ( $best_copy_length >= $from_segment_length / 2) {
Expand Down Expand Up @@ -655,6 +664,12 @@ private static function extractFragments($text, $delimiters) {
$start = $end = 0;
for (;;) {
$end += self::mb_strcspn($text, $delimiters, $end);
if ( $end === $start ) {
break;
}
$fragments[$start] = mb_substr($text, $start, $end - $start);
$start = $end;

$end += self::mb_strspn($text, $delimiters, $end);
if ( $end === $start ) {
break;
Expand Down