[v4] patch.py: Initialize git repo before patching

From: Pavel Zhukov <pavel.zhukov@huawei.com>

If PATCHTOOL="git" has been specified but workdir is not git repo
bitbake fails to apply the patches with error message:
Command Error: 'git rev-parse --show-toplevel' exited with 0  Output:
fatal: not a git repository (or any of the parent directories): .git

Fix this by initializing the repo before patching.
This allows binary git patches to be applied.

Signed-off-by: Pavel Zhukov <pavel.zhukov@huawei.com>
---
 meta/lib/oe/patch.py                    | 17 +++++++++++++++++
 meta/lib/oeqa/selftest/cases/bbtests.py |  6 ++++++
 2 files changed, 23 insertions(+)

On Wed, 2021-12-01 at 17:12 +0100, Pavel Zhukov wrote:
> From: Pavel Zhukov <pavel.zhukov@huawei.com>
> 
> If PATCHTOOL="git" has been specified but workdir is not git repo
> bitbake fails to apply the patches with error message:
> Command Error: 'git rev-parse --show-toplevel' exited with 0  Output:
> fatal: not a git repository (or any of the parent directories): .git
> 
> Fix this by initializing the repo before patching.
> This allows binary git patches to be applied.
> 
> Signed-off-by: Pavel Zhukov <pavel.zhukov@huawei.com>
> ---
>  meta/lib/oe/patch.py                    | 17 +++++++++++++++++
>  meta/lib/oeqa/selftest/cases/bbtests.py |  6 ++++++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/meta/lib/oe/patch.py b/meta/lib/oe/patch.py
> index fccbedb519..8326cb55bc 100644
> --- a/meta/lib/oe/patch.py
> +++ b/meta/lib/oe/patch.py
> @@ -56,6 +56,10 @@ def runcmd(args, dir = None):
>          if dir:
>              os.chdir(olddir)
>  
> +def getstatusoutput(cmd):
> +    import subprocess
> +    return subprocess.getstatusoutput(cmd.split())
> +

I'm not convinced this function is adding much or is needed. imports can just go
at the start of the python file in this case too.

>  class PatchError(Exception):
>      def __init__(self, msg):
>          self.msg = msg
> @@ -298,6 +302,19 @@ class GitApplyTree(PatchTree):
>          PatchTree.__init__(self, dir, d)
>          self.commituser = d.getVar('PATCH_GIT_USER_NAME')
>          self.commitemail = d.getVar('PATCH_GIT_USER_EMAIL')
> +        if not self._isInitialized():
> +            self._initRepo()
> +
> +    def _isInitialized(self):
> +        cmd = "git rev-parse --show-toplevel"
> +        (status, output) = getstatusoutput(cmd)
> +        ## Make sure we're in builddir to not break top-level git repos
> +        return status == 0 and os.path.samedir(output, self.dir)
> +
> +    def _initRepo(self):
> +        runcmd("git init".split(), self.dir)
> +        runcmd("git add .".split(), self.dir)
> +        runcmd("git commit -a --allow-empty -m Patching_started".split(), self.dir)
>  
>      @staticmethod
>      def extractPatchHeader(patchfile):
> diff --git a/meta/lib/oeqa/selftest/cases/bbtests.py b/meta/lib/oeqa/selftest/cases/bbtests.py
> index 6779e62103..2c3defc6b7 100644
> --- a/meta/lib/oeqa/selftest/cases/bbtests.py
> +++ b/meta/lib/oeqa/selftest/cases/bbtests.py
> @@ -297,3 +297,9 @@ INHERIT:remove = \"report-error\"
>  
>          test_recipe_summary_after = get_bb_var('SUMMARY', test_recipe)
>          self.assertEqual(expected_recipe_summary, test_recipe_summary_after)
> +
> +    def test_git_patchtool(self):
> +        self.write_recipeinc('man-db', 'PATCHTOOL=\"git\"')
> +        result = bitbake('man-db -c patch', ignore_status=False)
> +        self.delete_recipeinc('man-db')
> +        bitbake('-cclean man-db')

Can you add a comment here about what exactly we're testing please? If something
changes the way the man-db recipe works, this test will break (e.g. it became a
git based recipe rather than tarball).

We may also want to check that the man-db SRC_URI doesn't contain git:// to
guard against that and better document what the test is testing?

Cheers,

Richard