Improve GIT_EUSER handling

This adds giterr_user_cancel to return GIT_EUSER and clear any
error message that is sitting around.  As a result of using that
in places, we need to be more thorough with capturing errors that
happen inside a callback when used internally.  To help with that,
this also adds giterr_capture and giterr_restore so that when we
internally use a foreach-type function that clears errors and
converts them to GIT_EUSER, it is easier to restore not just the
return value, but the actual error message text.

4 files changed, 126 insertions, 21 deletions

diff --git a/tests/config/rename.c b/tests/config/rename.c
new file mode 100644
index 000000000..29ade7b00
--- /dev/null
+++ b/tests/config/rename.c
@@ -0,0 +1,82 @@
+#include "clar_libgit2.h"
+#include "config.h"
+
+static git_repository *g_repo = NULL;
+static git_config *g_config = NULL;
+
+void test_config_rename__initialize(void)
+{
+    g_repo = cl_git_sandbox_init("testrepo.git");
+	cl_git_pass(git_repository_config(&g_config, g_repo));
+}
+
+void test_config_rename__cleanup(void)
+{
+	git_config_free(g_config);
+	g_config = NULL;
+
+	cl_git_sandbox_cleanup();
+	g_repo = NULL;
+}
+
+void test_config_rename__can_rename(void)
+{
+	const git_config_entry *ce;
+
+	cl_git_pass(git_config_get_entry(
+		&ce, g_config, "branch.track-local.remote"));
+	cl_assert_equal_s(".", ce->value);
+
+	cl_git_fail(git_config_get_entry(
+		&ce, g_config, "branch.local-track.remote"));
+
+	cl_git_pass(git_config_rename_section(
+		g_repo, "branch.track-local", "branch.local-track"));
+
+	cl_git_pass(git_config_get_entry(
+		&ce, g_config, "branch.local-track.remote"));
+	cl_assert_equal_s(".", ce->value);
+
+	cl_git_fail(git_config_get_entry(
+		&ce, g_config, "branch.track-local.remote"));
+}
+
+void test_config_rename__prevent_overwrite(void)
+{
+	const git_config_entry *ce;
+	const git_error *err;
+
+	cl_git_pass(git_config_set_string(
+		g_config, "branch.local-track.remote", "yellow"));
+
+	cl_git_pass(git_config_get_entry(
+		&ce, g_config, "branch.local-track.remote"));
+	cl_assert_equal_s("yellow", ce->value);
+
+	cl_git_pass(git_config_rename_section(
+		g_repo, "branch.track-local", "branch.local-track"));
+
+	cl_git_pass(git_config_get_entry(
+		&ce, g_config, "branch.local-track.remote"));
+	cl_assert_equal_s(".", ce->value);
+
+//	cl_assert((err = giterr_last()) != NULL);
+//	cl_assert(err->message != NULL);
+}
+
+static void assert_invalid_config_section_name(
+	git_repository *repo, const char *name)
+{
+	cl_git_fail_with(
+		git_config_rename_section(repo, "branch.remoteless", name),
+		GIT_EINVALIDSPEC);
+}
+
+void test_config_rename__require_a_valid_new_name(void)
+{
+	assert_invalid_config_section_name(g_repo, "");
+	assert_invalid_config_section_name(g_repo, "bra\nch");
+	assert_invalid_config_section_name(g_repo, "branc#");
+	assert_invalid_config_section_name(g_repo, "bra\nch.duh");
+	assert_invalid_config_section_name(g_repo, "branc#.duh");
+}
diff --git a/tests/config/validkeyname.c b/tests/config/validkeyname.c
index 33699737b..0ef4a9ae3 100644
--- a/tests/config/validkeyname.c
+++ b/tests/config/validkeyname.c
@@ -46,23 +46,3 @@ void test_config_validkeyname__accessing_requires_a_valid_name(void)
 	assert_invalid_config_key_name("dif.dir\nstat.lines");
 	assert_invalid_config_key_name("dif.dirstat.li\nes");
 }
-
-static void assert_invalid_config_section_name(git_repository *repo, const char *name)
-{
-	cl_git_fail_with(git_config_rename_section(repo, "branch.remoteless", name), GIT_EINVALIDSPEC);
-}
-
-void test_config_validkeyname__renaming_a_section_requires_a_valid_name(void)
-{
-	git_repository *repo;
-
-	cl_git_pass(git_repository_open(&repo, cl_fixture("testrepo.git")));
-
-	assert_invalid_config_section_name(repo, "");
-	assert_invalid_config_section_name(repo, "bra\nch");
-	assert_invalid_config_section_name(repo, "branc#");
-	assert_invalid_config_section_name(repo, "bra\nch.duh");
-	assert_invalid_config_section_name(repo, "branc#.duh");
-
-	git_repository_free(repo);
-}
diff --git a/tests/config/write.c b/tests/config/write.c
index 15f750dc0..922d75557 100644
--- a/tests/config/write.c
+++ b/tests/config/write.c
@@ -303,3 +303,4 @@ void test_config_write__updating_a_locked_config_file_returns_ELOCKED(void)
 
 	git_config_free(cfg);
 }
+
diff --git a/tests/refs/branches/move.c b/tests/refs/branches/move.c
index ecf14e006..9d233de1a 100644
--- a/tests/refs/branches/move.c
+++ b/tests/refs/branches/move.c
@@ -66,12 +66,54 @@ void test_refs_branches_move__can_move_a_local_branch_to_a_partially_colliding_n
 void test_refs_branches_move__can_not_move_a_branch_if_its_destination_name_collide_with_an_existing_one(void)
 {
 	git_reference *original_ref, *new_ref;
+	git_config *config;
+	const git_config_entry *ce;
+	char *original_remote, *original_merge;
+
+	cl_git_pass(git_repository_config(&config, repo));
+
+	cl_git_pass(git_config_get_entry(&ce, config, "branch.master.remote"));
+	original_remote = strdup(ce->value);
+	cl_git_pass(git_config_get_entry(&ce, config, "branch.master.merge"));
+	original_merge  = strdup(ce->value);
+
 
 	cl_git_pass(git_reference_lookup(&original_ref, repo, "refs/heads/br2"));
 
-	cl_assert_equal_i(GIT_EEXISTS, git_branch_move(&new_ref, original_ref, "master", 0));
+	cl_assert_equal_i(GIT_EEXISTS,
+		git_branch_move(&new_ref, original_ref, "master", 0));
+
+	cl_assert(giterr_last()->message != NULL);
+	cl_git_pass(git_config_get_entry(&ce, config, "branch.master.remote"));
+	cl_assert_equal_s(original_remote, ce->value);
+	cl_git_pass(git_config_get_entry(&ce, config, "branch.master.merge"));
+	cl_assert_equal_s(original_merge,  ce->value);
+
+
+	cl_assert_equal_i(GIT_EEXISTS,
+		git_branch_move(&new_ref, original_ref, "cannot-fetch", 0));
+
+	cl_assert(giterr_last()->message != NULL);
+	cl_git_pass(git_config_get_entry(&ce, config, "branch.master.remote"));
+	cl_assert_equal_s(original_remote, ce->value);
+	cl_git_pass(git_config_get_entry(&ce, config, "branch.master.merge"));
+	cl_assert_equal_s(original_merge,  ce->value);
+
+	git_reference_free(original_ref);
+	cl_git_pass(git_reference_lookup(&original_ref, repo, "refs/heads/track-local"));
+
+	cl_assert_equal_i(GIT_EEXISTS,
+		git_branch_move(&new_ref, original_ref, "master", 0));
+
+	cl_assert(giterr_last()->message != NULL);
+	cl_git_pass(git_config_get_entry(&ce, config, "branch.master.remote"));
+	cl_assert_equal_s(original_remote, ce->value);
+	cl_git_pass(git_config_get_entry(&ce, config, "branch.master.merge"));
+	cl_assert_equal_s(original_merge,  ce->value);
 
+	free(original_remote); free(original_merge);
 	git_reference_free(original_ref);
+	git_config_free(config);
 }
 
 void test_refs_branches_move__moving_a_branch_with_an_invalid_name_returns_EINVALIDSPEC(void)