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  * For the examples below, we will assume that this is the change you want
11    to patch into your local checkout: https://codereview.appspot.com/6201055/
12  * These instructions should work on Mac or Linux; Windows is trickier,
13    because there is no standard Windows "patch" tool.
14
15See also:
16http://dev.chromium.org/developers/contributing-code#TOC-Instructions-for-Reviewer:-Checking-in-the-patch-for-a-non-committer
17
18If you use git cl, then you should be able to use the shortcut:
19
20~~~~
21git cl patch 6201055
22~~~~
23
24If you use gcl, or the above doesn't work, the following should always work.
25
261. Prepare your local workspace to accept the patch.
27
28    * cd into the root directory (usually trunk/) of the workspace where you
29      want to apply the patch.
30    * Make sure that the workspace is up-to-date and clean (or "updated and
31      clean enough" for your purposes).  If the codereview patch was against
32      an old revision of the repo, you may need to sync your local workspace
33      to that same revision...
34
352. Download the raw patch set.
36
37    * Open the codereview web page and look for the "Download raw patch set"
38      link near the upper right-hand corner.  Right-click on that link and copy
39      it to the clipboard.  (In my case, the link is
40      https://codereview.appspot.com/download/issue6201055_1.diff )
41    * If you are on Linux or Mac and have "curl" or "wget" installed, you can
42      download the patch from the command line:
43
44    ~~~~
45    curl https://codereview.appspot.com/download/issue6201055_1.diff
46    --output patch.txt
47    # or...
48    wget https://codereview.appspot.com/download/issue6201055_1.diff
49    --output-document=patch.txt
50    ~~~~
51
52    * Otherwise, figure out some other way to download this file and save it as
53      'patch.txt'
54
553. Apply this patch to your local checkout.
56
57    * You should still be in the root directory of the workspace where you want
58      to apply the patch.
59
60    ~~~~
61    patch -p1 <patch.txt
62    ~~~~
63
64    * Then you can run diff and visually check the local changes.
65
664. Complications: If the patch fails to apply, the following may be happening:
67
68   Wrong revision.  Maybe your local workspace is not up to date?  Or maybe the
69   patch was made against an old revision of the repository, and cannot be applied
70   to the latest revision?  (In that case, revert any changes and sync your
71   workspace to an older revision, then re-apply the patch.)
72
73