stash: use _an_ index not _the_ index

Don't manipulate the repository's index during stash; instead,
manipulate a temporary index and check it out.

This allows us to use the checkout mechanism to update the workdir and
the repository's index, and allows checkout to use its common mechanisms
to write data and handle errors.

1 files changed, 77 insertions, 28 deletions

diff --git a/src/stash.c b/src/stash.c
index b85a5e720..cb542a36c 100644
--- a/src/stash.c
+++ b/src/stash.c
@@ -12,6 +12,7 @@
 #include "message.h"
 #include "tree.h"
 #include "reflog.h"
+#include "blob.h"
 #include "git2/diff.h"
 #include "git2/stash.h"
 #include "git2/status.h"
@@ -103,19 +104,23 @@ cleanup:
 	return error;
 }
 
-static int build_tree_from_index(git_tree **out, git_index *index)
+static int build_tree_from_index(
+	git_tree **out,
+	git_repository *repo,
+	git_index *index)
 {
 	int error;
 	git_oid i_tree_oid;
 
-	if ((error = git_index_write_tree(&i_tree_oid, index)) < 0)
+	if ((error = git_index_write_tree_to(&i_tree_oid, index, repo)) < 0)
 		return error;
 
-	return git_tree_lookup(out, git_index_owner(index), &i_tree_oid);
+	return git_tree_lookup(out, repo, &i_tree_oid);
 }
 
 static int commit_index(
 	git_commit **i_commit,
+	git_repository *repo,
 	git_index *index,
 	const git_signature *stasher,
 	const char *message,
@@ -126,7 +131,7 @@ static int commit_index(
 	git_buf msg = GIT_BUF_INIT;
 	int error;
 
-	if ((error = build_tree_from_index(&i_tree, index)) < 0)
+	if ((error = build_tree_from_index(&i_tree, repo, index)) < 0)
 		goto cleanup;
 
 	if ((error = git_buf_printf(&msg, "index on %s\n", message)) < 0)
@@ -159,7 +164,38 @@ struct stash_update_rules {
 	bool include_ignored;
 };
 
+/*
+ * Similar to git_index_add_bypath but able to operate on any
+ * index without making assumptions about the repository's index
+ */
+static int stash_to_index(
+	git_repository *repo,
+	git_index *index,
+	const char *path)
+{
+	git_index *repo_index;
+	git_index_entry entry = {{0}};
+	struct stat st;
+	int error;
+
+	if (!git_repository_is_bare(repo) &&
+	    (error = git_repository_index__weakptr(&repo_index, repo)) < 0)
+		return error;
+
+	if ((error = git_blob__create_from_paths(
+	    &entry.id, &st, repo, NULL, path, 0, true)) < 0)
+		return error;
+
+	git_index_entry__init_from_stat(&entry, &st,
+		(repo_index != NULL || !repo_index->distrust_filemode));
+
+	entry.path = path;
+
+	return git_index_add(index, &entry);
+}
+
 static int stash_update_index_from_diff(
+	git_repository *repo,
 	git_index *index,
 	const git_diff *diff,
 	struct stash_update_rules *data)
@@ -205,7 +241,7 @@ static int stash_update_index_from_diff(
 		}
 
 		if (add_path != NULL)
-			error = git_index_add_bypath(index, add_path);
+			error = stash_to_index(repo, index, add_path);
 	}
 
 	return error;
@@ -213,17 +249,19 @@ static int stash_update_index_from_diff(
 
 static int build_untracked_tree(
 	git_tree **tree_out,
-	git_index *index,
+	git_repository *repo,
 	git_commit *i_commit,
 	uint32_t flags)
 {
+	git_index *i_index = NULL;
 	git_tree *i_tree = NULL;
 	git_diff *diff = NULL;
 	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
 	struct stash_update_rules data = {0};
 	int error;
 
-	git_index_clear(index);
+	if ((error = git_index_new(&i_index)) < 0)
+		goto cleanup;
 
 	if (flags & GIT_STASH_INCLUDE_UNTRACKED) {
 		opts.flags |= GIT_DIFF_INCLUDE_UNTRACKED |
@@ -240,24 +278,24 @@ static int build_untracked_tree(
 	if ((error = git_commit_tree(&i_tree, i_commit)) < 0)
 		goto cleanup;
 
-	if ((error = git_diff_tree_to_workdir(
-			&diff, git_index_owner(index), i_tree, &opts)) < 0)
+	if ((error = git_diff_tree_to_workdir(&diff, repo, i_tree, &opts)) < 0)
 		goto cleanup;
 
-	if ((error = stash_update_index_from_diff(index, diff, &data)) < 0)
+	if ((error = stash_update_index_from_diff(repo, i_index, diff, &data)) < 0)
 		goto cleanup;
 
-	error = build_tree_from_index(tree_out, index);
+	error = build_tree_from_index(tree_out, repo, i_index);
 
 cleanup:
 	git_diff_free(diff);
 	git_tree_free(i_tree);
+	git_index_free(i_index);
 	return error;
 }
 
 static int commit_untracked(
 	git_commit **u_commit,
-	git_index *index,
+	git_repository *repo,
 	const git_signature *stasher,
 	const char *message,
 	git_commit *i_commit,
@@ -268,7 +306,7 @@ static int commit_untracked(
 	git_buf msg = GIT_BUF_INIT;
 	int error;
 
-	if ((error = build_untracked_tree(&u_tree, index, i_commit, flags)) < 0)
+	if ((error = build_untracked_tree(&u_tree, repo, i_commit, flags)) < 0)
 		goto cleanup;
 
 	if ((error = git_buf_printf(&msg, "untracked files on %s\n", message)) < 0)
@@ -276,7 +314,7 @@ static int commit_untracked(
 
 	if ((error = git_commit_create(
 		&u_commit_oid,
-		git_index_owner(index),
+		repo,
 		NULL,
 		stasher,
 		stasher,
@@ -287,7 +325,7 @@ static int commit_untracked(
 		NULL)) < 0)
 		goto cleanup;
 
-	error = git_commit_lookup(u_commit, git_index_owner(index), &u_commit_oid);
+	error = git_commit_lookup(u_commit, repo, &u_commit_oid);
 
 cleanup:
 	git_tree_free(u_tree);
@@ -316,10 +354,10 @@ static git_diff_delta *stash_delta_merge(
 
 static int build_workdir_tree(
 	git_tree **tree_out,
-	git_index *index,
+	git_repository *repo,
+	git_index *i_index,
 	git_commit *b_commit)
 {
-	git_repository *repo = git_index_owner(index);
 	git_tree *b_tree = NULL;
 	git_diff *diff = NULL, *idx_to_wd = NULL;
 	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
@@ -331,17 +369,17 @@ static int build_workdir_tree(
 	if ((error = git_commit_tree(&b_tree, b_commit)) < 0)
 		goto cleanup;
 
-	if ((error = git_diff_tree_to_index(&diff, repo, b_tree, index, &opts)) < 0 ||
-		(error = git_diff_index_to_workdir(&idx_to_wd, repo, index, &opts)) < 0 ||
+	if ((error = git_diff_tree_to_index(&diff, repo, b_tree, i_index, &opts)) < 0 ||
+		(error = git_diff_index_to_workdir(&idx_to_wd, repo, i_index, &opts)) < 0 ||
 		(error = git_diff__merge(diff, idx_to_wd, stash_delta_merge)) < 0)
 		goto cleanup;
 
 	data.include_changed = true;
 
-	if ((error = stash_update_index_from_diff(index, diff, &data)) < 0)
+	if ((error = stash_update_index_from_diff(repo, i_index, diff, &data)) < 0)
 		goto cleanup;
 
-	error = build_tree_from_index(tree_out, index);
+	error = build_tree_from_index(tree_out, repo, i_index);
 
 cleanup:
 	git_diff_free(idx_to_wd);
@@ -353,7 +391,7 @@ cleanup:
 
 static int commit_worktree(
 	git_oid *w_commit_oid,
-	git_index *index,
+	git_repository *repo,
 	const git_signature *stasher,
 	const char *message,
 	git_commit *i_commit,
@@ -362,7 +400,9 @@ static int commit_worktree(
 {
 	int error = 0;
 	git_tree *w_tree = NULL, *i_tree = NULL;
+	git_index *i_index = NULL;
 	const git_commit *parents[] = {	NULL, NULL,	NULL };
+	int ignorecase;
 
 	parents[0] = b_commit;
 	parents[1] = i_commit;
@@ -371,15 +411,21 @@ static int commit_worktree(
 	if ((error = git_commit_tree(&i_tree, i_commit)) < 0)
 		goto cleanup;
 
-	if ((error = git_index_read_tree(index, i_tree)) < 0)
+	if ((error = git_index_new(&i_index)) < 0 ||
+		(error = git_repository__cvar(&ignorecase, repo, GIT_CVAR_IGNORECASE)) < 0)
+		goto cleanup;
+
+	git_index__set_ignore_case(i_index, ignorecase);
+
+	if ((error = git_index_read_tree(i_index, i_tree)) < 0)
 		goto cleanup;
 
-	if ((error = build_workdir_tree(&w_tree, index, b_commit)) < 0)
+	if ((error = build_workdir_tree(&w_tree, repo, i_index, b_commit)) < 0)
 		goto cleanup;
 
 	error = git_commit_create(
 		w_commit_oid,
-		git_index_owner(index),
+		repo,
 		NULL,
 		stasher,
 		stasher,
@@ -392,6 +438,7 @@ static int commit_worktree(
 cleanup:
 	git_tree_free(i_tree);
 	git_tree_free(w_tree);
+	git_index_free(i_index);
 	return error;
 }
 
@@ -534,12 +581,12 @@ int git_stash_save(
 		goto cleanup;
 
 	if ((error = commit_index(
-			&i_commit, index, stasher, git_buf_cstr(&msg), b_commit)) < 0)
+			&i_commit, repo, index, stasher, git_buf_cstr(&msg), b_commit)) < 0)
 		goto cleanup;
 
 	if ((flags & (GIT_STASH_INCLUDE_UNTRACKED | GIT_STASH_INCLUDE_IGNORED)) &&
 		(error = commit_untracked(
-			&u_commit, index, stasher, git_buf_cstr(&msg),
+			&u_commit, repo, stasher, git_buf_cstr(&msg),
 			i_commit, flags)) < 0)
 		goto cleanup;
 
@@ -547,7 +594,7 @@ int git_stash_save(
 		goto cleanup;
 
 	if ((error = commit_worktree(
-			out, index, stasher, git_buf_cstr(&msg),
+			out, repo, stasher, git_buf_cstr(&msg),
 			i_commit, b_commit, u_commit)) < 0)
 		goto cleanup;
 
@@ -738,6 +785,8 @@ static void normalize_apply_options(
 		memcpy(opts, &default_apply_opts, sizeof(git_stash_apply_options));
 	}
 
+	opts->checkout_options.checkout_strategy |= GIT_CHECKOUT_NO_REFRESH;
+
 	if (!opts->checkout_options.our_label)
 		opts->checkout_options.our_label = "Updated upstream";