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patch_fromText and lines breaks issue in Python #157
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Same problem, just tested in Javascript :
// Import the diff-match-patch library const DiffMatchPatch = require('diff-match-patch'); const dmp = new DiffMatchPatch(); // Original JSON string const originalJson = `{ "type": "module", "dependencies": { "ejs": "^3.1.9", "express": "^4.18.2", "puppeteer": "^21.7.0" } }`; // Expected JSON string with a new dependency added const expectedJson = `{ "type": "module", "dependencies": { "ejs": "^3.1.9", "express": "^4.18.2", "lodash": "^4.17.21", "puppeteer": "^21.7.0" } }`; // Unidiff string representing the change const diffStr = '@@ -82,16 +82,42 @@\n .18.2",\n+ "lodash": "^4.17.21",\n "pup'; console.log("____________ BROKEN EXAMPLE"); // Converting the diff string to patches let patches = dmp.patch_fromText(diffStr); // Converting patches back to a diff string for display let patchText = dmp.patch_toText(patches); // Applying patches to the original JSON string let [newText, results] = dmp.patch_apply(patches, originalJson); console.log(patchText); console.log(newText); console.log("____________ WORKING EXAMPLE"); // Creating patches directly from original and expected JSON strings patches = dmp.patch_make(originalJson, expectedJson); // Converting patches to a diff string for display patchText = dmp.patch_toText(patches); // Applying these patches to the original JSON [newText, results] = dmp.patch_apply(patches, originalJson); console.log(patchText); console.log(newText);Result
____________ BROKEN EXAMPLE @@ -82,16 +82,42 @@ .18.2%22, + %22lodash%22: %22%5E4.17.21%22, %22pup { "type": "module", "dependencies": { "ejs": "^3.1.9", "express": "^4.18.2", "lodash": "^4.17.21", "puppeteer": "^21.7.0" } } ____________ WORKING EXAMPLE @@ -82,16 +82,42 @@ .18.2%22,%0A + %22lodash%22: %22%5E4.17.21%22,%0A %22pup { "type": "module", "dependencies": { "ejs": "^3.1.9", "express": "^4.18.2", "lodash": "^4.17.21", "puppeteer": "^21.7.0" } }there one thing that stands out: in the broken example we have a patch file where the newline is percent-encoded as
%0A. it's becoming part of the diff, but the patch tool already works on the line-level.makes me wonder if there's something about the
diffoutput thatpatchtakes that makes an assumption about a single trailing newline vs. many. as in, maybediff-match-patchshould strip a single trailing newline from its output before percent-encoding it.@dmsnell I just encountered this issue myself. This bug is troublesome. Do you plan to fix it and publish the fix in your improved fork? ( https://github.com/dmsnell/diff-match-patch )? That would be great. Can't believe Google abandoned this project... 😔
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Reacted by 17351269
Hello,
I am looking to utilize this fantastic library for applying patches to a file, but I'm encountering issues with broken line breaks. I have attempted to use the patch_make function to compare the behavior, and it operates effectively when the diff is generated by dmp. Could someone please guide me in identifying the potential issues in my diff file?
The wrong result :
The expected one :
This is my simple test code :
And the result
We can clearely see that dmp adds a "%0A" (an encoded \n) in the generated patch, which is missing when creating it from text.
Version info :