1Applying patches
2================
3
4If you are a Skia committer and have been asked to commit an
5externally-submitted patch, this is how to do it.  (This technique is useful in
6other situations too, like if you just want to try out somebody else's patch
7locally.)
8
9Notes:
10
11  * For the examples below, we will assume that this is the change you want
12    to patch into your local checkout: https://codereview.appspot.com/6201055/
13  * These instructions should work on Mac or Linux; Windows is trickier,
14    because there is no standard Windows "patch" tool.
15
16See also [Contributing Code for The Chromium Projects]
17(http://dev.chromium.org/developers/contributing-code#TOC-Instructions-for-Reviewer:-Checking-in-the-patch-for-a-non-committer).
18
19If you use `git cl`, then you should be able to use the shortcut:
20
21~~~~
22git cl patch 6201055
23~~~~
24
25If you use `gcl`, or the above doesn't work, the following should always work.
26
271. Prepare your local workspace to accept the patch.
28
29    * cd into the root directory (usually `trunk/`) of the workspace where you
30      want to apply the patch.
31    * Make sure that the workspace is up-to-date and clean (or "updated and
32      clean enough" for your purposes).  If the codereview patch was against
33      an old revision of the repo, you may need to sync your local workspace
34      to that same revision.
35
362. Download the raw patch set.
37
38    * Open the codereview web page and look for the "Download raw patch set"
39      link near the upper right-hand corner.  Right-click on that link and copy
40      it to the clipboard.  (In my case, the link is
41      https://codereview.appspot.com/download/issue6201055_1.diff )
42    * If you are on Linux or Mac and have "curl" or "wget" installed, you can
43      download the patch from the command line:
44
45    ~~~~
46    curl https://codereview.appspot.com/download/issue6201055_1.diff
47    --output patch.txt
48    # or...
49    wget https://codereview.appspot.com/download/issue6201055_1.diff
50    --output-document=patch.txt
51    ~~~~
52
53    * Otherwise, figure out some other way to download this file and save it as
54      `patch.txt`
55
563. Apply this patch to your local checkout.
57
58    * You should still be in the root directory of the workspace where you want
59      to apply the patch.
60
61    ~~~~
62    patch -p1 <patch.txt
63    ~~~~
64
65    * Then you can run `diff` and visually check the local changes.
66
674. Complications: If the patch fails to apply, the following may be happening:
68
69    * Wrong revision.  Maybe your local workspace is not up to date?  Or maybe the
70      patch was made against an old revision of the repository, and cannot be applied
71      to the latest revision?  (In that case, revert any changes and sync your
72      workspace to an older revision, then re-apply the patch.)
73
74