Merge branch 'bc/use-sha256-by-default-in-3.0'

Prepare to flip the default hash function to SHA-256.

* bc/use-sha256-by-default-in-3.0:
  Enable SHA-256 by default in breaking changes mode
  help: add a build option for default hash
  t5300: choose the built-in hash outside of a repo
  t4042: choose the built-in hash outside of a repo
  t1007: choose the built-in hash outside of a repo
  t: default to compile-time default hash if not set
  setup: use the default algorithm to initialize repo format
  Use legacy hash for legacy formats
  builtin: use default hash when outside a repository
  hash: add a constant for the legacy hash algorithm
  hash: add a constant for the default hash algorithm

diff --cc builtin/diff.c
Simple merge

diff --cc builtin/hash-object.c
Simple merge

diff --cc builtin/index-pack.c
Simple merge

diff --cc builtin/receive-pack.c
Simple merge

diff --cc builtin/shortlog.c
Simple merge

diff --cc bundle.c
Simple merge

diff --cc fetch-pack.c
Simple merge

diff --cc hash.h
Simple merge

diff --cc help.c
index 89cd47e3b867f789414fa25e48d8703ca36659ea,bd0be2ee574cc90e9f77ca5ab2b1bfcec6eb4efe..652efebf00c309f054ab9389e6c3e65d278e7c10
--- 1/help.c
--- 2/help.c
+++ b/help.c
@@@ -810,8 -810,7 +810,9 @@@ void get_version_info(struct strbuf *bu
                            SHA1_UNSAFE_BACKEND);
  #endif
                strbuf_addf(buf, "SHA-256: %s\n", SHA256_BACKEND);
 +              strbuf_addf(buf, "default-ref-format: %s\n",
 +                          ref_storage_format_to_name(REF_STORAGE_FORMAT_DEFAULT));
+               strbuf_addf(buf, "default-hash: %s\n", hash_algos[GIT_HASH_DEFAULT].name);
        }
  }
  

diff --cc setup.c
Simple merge

diff --cc t/t1007-hash-object.sh
Simple merge

diff --cc t/t5300-pack-object.sh
Simple merge

diff --cc t/test-lib-functions.sh
Simple merge

diff --cc t/test-lib.sh
Simple merge