Summary

Handle Mercurial diffs as byte strings

Review Request #7184 — Created April 9, 2015 and submitted April 14, 2015, 3:13 p.m.

Information

Owner

halvorlu

Repository

RBTools

Branch

master

Bugs

Depends On

Commit

bc8978d...

Reviewers

Groups

rbtools

People

Description

Mercurial diffs were previously treated as UTF-8 strings, which may fail if the file has another encoding. It may cause utils.process.execute to raise a UnicodeDecodeError, since it decoded with only UTF-8.

I have changed clients.mercurial to supply "results_unicode=False" when running the diff command. This seems to be in line with what is done in clients.git and clients.svn.

Testing Done


Used rbt post to upload a diff that converts a file (with non-ASCII characters) from UTF-8 to Latin-1, and vice versa, with success.
Used rbt patch to apply the diffs

Tool: Pyflakes
Processed Files:
    rbtools/utils/process.py



Tool: PEP8 Style Checker
Processed Files:
    rbtools/utils/process.py

Summary:

-	Handle diffs that contain Latin-1 characters.
+	[WIP] Handle diffs that contain Latin-1 characters.

Testing Done:

		I've used rbt post to upload a diff that contains both UTF-8 and Latin-1 characters, with success.
	+
	+	After testing it some more it seems that Reviewboard may have trouble interpreting the diff.

Summary:

-	[WIP] Handle diffs that contain Latin-1 characters.
+	Handle diffs that contain Latin-1 characters.

Testing Done:

		I've used rbt post to upload a diff that contains both UTF-8 and Latin-1 characters, with success.
-
-		After testing it some more it seems that Reviewboard may have trouble interpreting the diff.

Thanks for the change!

Something I want to bring up for discussion to a wider audience is whether we should even be interpreting any of this as utf-8. I believe we should be expecting any diff output to be in any encoding and just read it as bytestrings, uploading to the server as-is.

I'm sure there are things we need to treat as utf-8, but diffs should probably not be one of those things.

halvorlu April 9, 2015, 3:04 p.m.

I absolutely agree. Preserving the diff as a byte string is probably the best way to ensure that it is "correct", in the sense that you preserve all information in it, regardless of what encoding your file may have. But I imagine this may require quite a few changes both in RBTools and ReviewBoard?

chipx86 April 9, 2015, 3:06 p.m.

Review Board is doing the correct thing now with handling these as byte strings. RBTools is, iirc, generating byte strings when sending requests to the server. I suspect it should be fine to move back to bytestrings for diff generation. There may be some corner cases we'll have to solve as a result of that (particularly with any diff parsing/generation code that lives in RBTools), but it won't be any worse than today.

halvorlu April 11, 2015, 10:36 a.m.

As you may have seen, I found a better and much simpler solution: to supply results_unicode=False to utils.process.execute. This seems to be in line with what is done for e.g. git and SVN.

Change Summary:

A much simpler and better solution: Just supply results_unicode=False to utils.process.execute.

Summary:

-	Handle diffs that contain Latin-1 characters.
+	Handle Mercurial diffs as byte strings

Description:

~		If "hg diff" and "git diff" process a file that is (or was) encoded in Latin-1 (and contains non-ASCII characters), their output would cause rbtools.utils.process.execute to raise a UnicodeDecodeError, since it decoded with only UTF-8.
	~	Mercurial diffs were previously treated as UTF-8 strings, which may fail if the file has another encoding. It may cause utils.process.execute to raise a UnicodeDecodeError, since it decoded with only UTF-8.

~		I have added handling of output from commands that contain both UTF-8 and/or Latin-1 characters, by decoding the output line by line, trying both UTF-8 and Latin-1. This allows handling of diffs for Latin-1 files, and files that change encoding to/from UTF-8 from/to Latin-1.
	~	I have changed clients.mercurial to supply "results_unicode=False" when running the diff command. This seems to be in line with what is done in clients.git and clients.svn.
-		More encodings could possibly considered if desired, but I've chosen Latin-1 since it seems most common (apart from UTF-8).

Testing Done:

~		I've used rbt post to upload a diff that contains both UTF-8 and Latin-1 characters, with success.
	~	Used rbt post to upload a diff that converts a file (with non-ASCII characters) from UTF-8 to Latin-1, and vice versa, with success.
	+	Used rbt patch to apply the diffs

Commit:

-	9714db260185f4d5359527d0182b44dbb5a10b2a
+	bc8978d648aae43f1d43f7c54b5b83a7cb27a534

Diff:

Revision 2 (+2 -2)

Show changes

rbtools/clients/mercurial.py

Tool: Pyflakes
Processed Files:
    rbtools/clients/mercurial.py



Tool: PEP8 Style Checker
Processed Files:
    rbtools/clients/mercurial.py

Ship it!

```
Ship It!
```

Status: Closed (submitted)

Change Summary:

Pushed to release-0.7.x (2aedcf9)