oeqa/selftest/oelib/buildhistory: git default branch

On hosts with git defaulting to main branch the following exception
occures:

File .../buildhistory.py", line 99, in test_compare_dict_blobs_default
  blob1 = self.repo.heads.master.commit.tree.blobs[0]
          ^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.12/site-packages/git/util.py", line 1114, in __getattr__
  return list.__getattribute__(self, attr)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'IterableList' object has no attribute 'master'

Support main and master branch for these test cases.

Note: setting the default branch with --initial-branch requires git
version 2.28 or later. Some of the still supported host distros do not
provide this feature yet.

(From OE-Core rev: 7df99843d8f31d8e0c2872ff625f4a5abf28f740)

Signed-off-by: Adrian Freihofer <adrian.freihofer@siemens.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oeqa/selftest/cases/oelib/buildhistory.py

@@ -30,6 +30,16 @@ class TestBlobParsing(OESelftestTestCase):
         import shutil
         shutil.rmtree(self.repo_path)
 
+    @property
+    def heads_default(self):
+        """
+        Support repos defaulting to master or to main branch
+        """
+        try:
+            return self.repo.heads.main
+        except AttributeError:
+            return self.repo.heads.master
+
     def commit_vars(self, to_add={}, to_remove = [], msg="A commit message"):
         if len(to_add) == 0 and len(to_remove) == 0:
             return
@@ -67,10 +77,10 @@ class TestBlobParsing(OESelftestTestCase):
         changesmap = { "foo-2" : ("2", "8"), "bar" : ("","4"), "bar-2" : ("","5")}
 
         self.commit_vars(to_add = { "foo" : "1", "foo-2" : "2", "foo-3" : "3" })
-        blob1 = self.repo.heads.master.commit.tree.blobs[0]
+        blob1 = self.heads_default.commit.tree.blobs[0]
 
         self.commit_vars(to_add = { "foo-2" : "8", "bar" : "4", "bar-2" : "5" })
-        blob2 = self.repo.heads.master.commit.tree.blobs[0]
+        blob2 = self.heads_default.commit.tree.blobs[0]
 
         change_records = compare_dict_blobs(os.path.join(self.repo_path, self.test_file),
             blob1, blob2, False, False)
@@ -86,10 +96,10 @@ class TestBlobParsing(OESelftestTestCase):
         defaultmap = { x : ("default", "1")  for x in ["PKG", "PKGE", "PKGV", "PKGR"]}
 
         self.commit_vars(to_add = { "foo" : "1" })
-        blob1 = self.repo.heads.master.commit.tree.blobs[0]
+        blob1 = self.heads_default.commit.tree.blobs[0]
 
         self.commit_vars(to_add = { "PKG" : "1", "PKGE" : "1", "PKGV" : "1", "PKGR" : "1" })
-        blob2 = self.repo.heads.master.commit.tree.blobs[0]
+        blob2 = self.heads_default.commit.tree.blobs[0]
 
         change_records = compare_dict_blobs(os.path.join(self.repo_path, self.test_file),
             blob1, blob2, False, False)