bitbake: bitbake: tests/fetch: Set git config if not already set

git config returns an error code if user.email or user.name are not set,
so bb.process.run raises an ExecutionError, failing the test.

Improve the logic by catching the ExectionError and using this to set a
default value.

Change a direct invocation of 'git init' to use self.git_init so that
it follows the code path above.

Remove the related comment from the README now that git sets up the user
details automatically.

(Bitbake rev: 0c7079d0609a13713b890a9675abd9fba032f199)

Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/tests/fetch.py

@@ -429,9 +429,15 @@ class FetcherTest(unittest.TestCase):
         # a common setup is to use other default
         # branch than master.
         self.git(['checkout', '-b', 'master'], cwd=cwd)
-        if not self.git(['config', 'user.email'], cwd=cwd):
+
+        try:
+            self.git(['config', 'user.email'], cwd=cwd)
+        except bb.process.ExecutionError:
             self.git(['config', 'user.email', 'you@example.com'], cwd=cwd)
-        if not self.git(['config', 'user.name'], cwd=cwd):
+
+        try:
+            self.git(['config', 'user.name'], cwd=cwd)
+        except bb.process.ExecutionError:
             self.git(['config', 'user.name', 'Your Name'], cwd=cwd)
 
 class MirrorUriTest(FetcherTest):
@@ -3038,7 +3044,7 @@ class FetchPremirroronlyLocalTest(FetcherTest):
         self.mirrorname = "git2_git.fake.repo.bitbake.tar.gz"
         recipeurl = "git:/git.fake.repo/bitbake"
         os.makedirs(self.gitdir)
-        self.git("init", self.gitdir)
+        self.git_init(cwd=self.gitdir)
         for i in range(0):
             self.git_new_commit()
         bb.process.run('tar -czvf {} .'.format(os.path.join(self.mirrordir, self.mirrorname)), cwd =  self.gitdir)