Improve diff config options handling

This makes diff use the cvar cache for config options where
possible, and also adds support for a number of other config
options to diff including "diff.context", "diff.ignoreSubmodules",
"diff.noprefix", "diff.mnemonicprefix", and "core.abbrev".

To make this natural, this involved a rearrangement of the code
that allocates the diff object vs. the code that initializes it
based on the combination of options passed in by the user and
read from the config.

This commit includes tests for most of these new options as well.

1 files changed, 78 insertions, 0 deletions

diff --git a/tests-clar/diff/patch.c b/tests-clar/diff/patch.c
index d41f3f12d..40b191dd5 100644
--- a/tests-clar/diff/patch.c
+++ b/tests-clar/diff/patch.c
@@ -135,6 +135,84 @@ void test_diff_patch__to_string(void)
 	git_tree_free(one);
 }
 
+void test_diff_patch__config_options(void)
+{
+	const char *one_sha = "26a125e"; /* current HEAD */
+	git_tree *one;
+	git_config *cfg;
+	git_diff_list *diff;
+	git_diff_patch *patch;
+	char *text;
+	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
+	char *onefile = "staged_changes_modified_file";
+	const char *expected1 = "diff --git c/staged_changes_modified_file i/staged_changes_modified_file\nindex 70bd944..906ee77 100644\n--- c/staged_changes_modified_file\n+++ i/staged_changes_modified_file\n@@ -1 +1,2 @@\n staged_changes_modified_file\n+staged_changes_modified_file\n";
+	const char *expected2 = "diff --git i/staged_changes_modified_file w/staged_changes_modified_file\nindex 906ee77..011c344 100644\n--- i/staged_changes_modified_file\n+++ w/staged_changes_modified_file\n@@ -1,2 +1,3 @@\n staged_changes_modified_file\n staged_changes_modified_file\n+staged_changes_modified_file\n";
+	const char *expected3 = "diff --git staged_changes_modified_file staged_changes_modified_file\nindex 906ee77..011c344 100644\n--- staged_changes_modified_file\n+++ staged_changes_modified_file\n@@ -1,2 +1,3 @@\n staged_changes_modified_file\n staged_changes_modified_file\n+staged_changes_modified_file\n";
+	const char *expected4 = "diff --git staged_changes_modified_file staged_changes_modified_file\nindex 70bd9443ada0..906ee7711f4f 100644\n--- staged_changes_modified_file\n+++ staged_changes_modified_file\n@@ -1 +1,2 @@\n staged_changes_modified_file\n+staged_changes_modified_file\n";
+
+	g_repo = cl_git_sandbox_init("status");
+	cl_git_pass(git_repository_config(&cfg, g_repo));
+	one = resolve_commit_oid_to_tree(g_repo, one_sha);
+	opts.pathspec.count = 1;
+	opts.pathspec.strings = &onefile;
+
+
+	cl_git_pass(git_config_set_string(cfg, "diff.mnemonicprefix", "true"));
+
+	cl_git_pass(git_diff_tree_to_index(&diff, g_repo, one, NULL, &opts));
+
+	cl_assert_equal_i(1, (int)git_diff_num_deltas(diff));
+	cl_git_pass(git_diff_get_patch(&patch, NULL, diff, 0));
+	cl_git_pass(git_diff_patch_to_str(&text, patch));
+	cl_assert_equal_s(expected1, text);
+
+	git__free(text);
+	git_diff_patch_free(patch);
+	git_diff_list_free(diff);
+
+	cl_git_pass(git_diff_index_to_workdir(&diff, g_repo, NULL, &opts));
+
+	cl_assert_equal_i(1, (int)git_diff_num_deltas(diff));
+	cl_git_pass(git_diff_get_patch(&patch, NULL, diff, 0));
+	cl_git_pass(git_diff_patch_to_str(&text, patch));
+	cl_assert_equal_s(expected2, text);
+
+	git__free(text);
+	git_diff_patch_free(patch);
+	git_diff_list_free(diff);
+
+
+	cl_git_pass(git_config_set_string(cfg, "diff.noprefix", "true"));
+
+	cl_git_pass(git_diff_index_to_workdir(&diff, g_repo, NULL, &opts));
+
+	cl_assert_equal_i(1, (int)git_diff_num_deltas(diff));
+	cl_git_pass(git_diff_get_patch(&patch, NULL, diff, 0));
+	cl_git_pass(git_diff_patch_to_str(&text, patch));
+	cl_assert_equal_s(expected3, text);
+
+	git__free(text);
+	git_diff_patch_free(patch);
+	git_diff_list_free(diff);
+
+
+	cl_git_pass(git_config_set_int32(cfg, "core.abbrev", 12));
+
+	cl_git_pass(git_diff_tree_to_index(&diff, g_repo, one, NULL, &opts));
+
+	cl_assert_equal_i(1, (int)git_diff_num_deltas(diff));
+	cl_git_pass(git_diff_get_patch(&patch, NULL, diff, 0));
+	cl_git_pass(git_diff_patch_to_str(&text, patch));
+	cl_assert_equal_s(expected4, text);
+
+	git__free(text);
+	git_diff_patch_free(patch);
+	git_diff_list_free(diff);
+
+	git_tree_free(one);
+	git_config_free(cfg);
+}
+
 void test_diff_patch__hunks_have_correct_line_numbers(void)
 {
 	git_config *cfg;