tests: write commit-graph with Bloom filters

The GIT_TEST_COMMIT_GRAPH environment variable updates the commit-
graph file whenever "git commit" is run, ensuring that we always
have an updated commit-graph throughout the test suite. The
GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS environment variable was
introduced to write the changed-path Bloom filters whenever "git
commit-graph write" is run. However, the GIT_TEST_COMMIT_GRAPH
trick doesn't launch a separate process and instead writes it
directly.

To expand the number of tests that have commits in the commit-graph
file, add a helper method that computes the commit-graph and place
that helper inside "git commit" and "git merge".

In the helper method, check GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS
to ensure we are writing changed-path Bloom filters whenever
possible.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/commit-graph.h b/commit-graph.h
index 8655d064c1..39484482cc 100644
--- a/commit-graph.h
+++ b/commit-graph.h
@@ -11,6 +11,15 @@
 #define GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD "GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD"
 #define GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS "GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS"
 
+/*
+ * This method is only used to enhance coverage of the commit-graph
+ * feature in the test suite with the GIT_TEST_COMMIT_GRAPH and
+ * GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS environment variables. Do not
+ * call this method oustide of a builtin, and only if you know what
+ * you are doing!
+ */
+void git_test_write_commit_graph_or_die(void);
+
 struct commit;
 struct bloom_filter_settings;