diff-match-patch
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Diff breaks unicode characters for emojis
I'm working message log in our app. We want to show diff of changes any user made on text posts. Those posts may include emoji characters but diff_match_patch replaces those characters with � character (but only if they changed in the text).
The behaviour can be reproduced here: https://neil.fraser.name/software/diff_match_patch/demos/diff.html
Paste 😉and 😀into textareas and compute the diff.
Why is this happening?
Looks like the diffing doesn't consider whether a character is non-ASCII and breaks unicode emojis in pieces if they are different but occupy the same space. That would result in some unknown character � after all is said and done. Assuming it's conversion related.
Looking into it out of curiosity.
Looks like @yetanotherape has solved it for their PHP fork:
- https://github.com/yetanotherape/diff-match-patch/issues/9
- https://github.com/yetanotherape/diff-match-patch/commit/3e7b0241a06b20ad348c1d35f77204d02ec346bc
The two current attempts at solving it in this repo have both had complications:
- https://github.com/google/diff-match-patch/pull/13
- https://github.com/google/diff-match-patch/pull/69
Any updates here?
@ndvbd I ended up "solving" it by just escaping all the special unicode stuff with text = encodeURI(text)
before saving the text (and using decodeURI(...)
to undo it, of course). Bit of a hack but it works for my use case.
Check out #80, as referenced above @ndvbd's comment. It should handle all the surrogate pairs properly.