rn-117: add article about dumb http bug

Author: chriscool

rev_news/drafts/edition-117.md

@@ -25,9 +25,68 @@ This edition covers what happened during the months of October and November 2024
 ### Reviews
 -->
 
-<!---
 ### Support
--->
+
++[Bug report: v2.47.0 cannot fetch version 1 pack indexes](https://lore.kernel.org/git/[email protected]/)
+
+ Someone called 'fox' reported that when upgrading Git to v2.47.0
+ from v2.46.2 or a previous version, cloning from their website,
+ which uses the old "dumb HTTP" protocol, stopped working. With
+ v2.47.0 there is an error message indicating that some index files
+ "differ in contents".
+
+ Using `git bisect` fox found the commit that introduced the
+ issue. That commit implemented a check that verified that the index
+ file downloaded from the remote was byte-for-byte identical with the
+ index file generated locally from the Git objects downloaded as part
+ of the clone.
+
+ That check failed because the remote had an index in the version 1
+ format, while the locally generated index was in a more recent
+ format. And fox wondered if this was intentional.
+
+ Eric Sunshine replied to fox that he could reproduce the problem.
+
+ Jeff King, alias Peff, also replied to fox saying that the breakage
+ was not intended. He thought that it was better to rely on the
+ locally generated index, but that there should be no guarantee for
+ it to be identical to the one downloaded.
+
+ Peff proposed a draft patch that discarded the downloaded version
+ before generating an index, but said it was hacky and didn't check
+ that the content was the same. So he suggested a better solution.
+
+ He then proposed an improved draft patch, which implemented the
+ better solution he had suggested by marking the downloaded index as
+ temporary and then discarding it after a new one is generated.
+
+ Taylor Blau, who was the temporary Git maintainer while Junio
+ Hamano, the usual maintainer, had some time off, replied to Eric and
+ fox in the meantime confirming it was an unintentional breakage, and
+ saying he was going to look at Peff's patches.
+
+ Taylor then discussed with Peff the first draft patch and agreed
+ with Peff that the solution implemented in the improved draft patch
+ was better.
+
+ So Taylor reviewed Peff's improved draft patch. He made some
+ comments but found it good, and asked Peff to add a test and to
+ propose it as a regular patch.
+
+ Peff replied to Taylor's comments, proposed a draft test, and said
+ he was going to work on a proper patch as well as some cleanups and
+ refactors in the dumb HTTP code.
+
+ Taylor found Peff's draft test "beautifully written".
+
+ Peff then sent
+[a series made of 11 patches](https://lore.kernel.org/git/[email protected]/)
+ to fix the issue, cleanup the dumb HTTP code and fix a couple of
+ other bugs or potential bugs he found in the process.
+
+ Taylor reviewed the patch series and discussed a few technical
+ details with Peff. Overall he found the series good to go and
+ eventually merged it.
 
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