Further EUSER and error propagation fixes

This continues auditing all the places where GIT_EUSER is being
returned and making sure to clear any existing error using the
new giterr_user_cancel helper.  As a result, places that relied
on intercepting GIT_EUSER but having the old error preserved also
needed to be cleaned up to correctly stash and then retrieve the
actual error.

Additionally, as I encountered places where error codes were not
being propagated correctly, I tried to fix them up.  A number of
those fixes are included in the this commit as well.

1 files changed, 25 insertions, 22 deletions

diff --git a/src/pack-objects.c b/src/pack-objects.c
index 2d62507f2..ac0615064 100644
--- a/src/pack-objects.c
+++ b/src/pack-objects.c
@@ -32,6 +32,7 @@ struct unpacked {
 struct tree_walk_context {
 	git_packbuilder *pb;
 	git_buf buf;
+	git_error_state error;
 };
 
 struct pack_write_context {
@@ -220,12 +221,15 @@ int git_packbuilder_insert(git_packbuilder *pb, const git_oid *oid,
 
 	if (pb->progress_cb) {
 		double current_time = git__timer();
-		if ((current_time - pb->last_progress_report_time) >= MIN_PROGRESS_UPDATE_INTERVAL) {
+		double elapsed = current_time - pb->last_progress_report_time;
+
+		if (elapsed >= MIN_PROGRESS_UPDATE_INTERVAL) {
 			pb->last_progress_report_time = current_time;
-			if (pb->progress_cb(GIT_PACKBUILDER_ADDING_OBJECTS, pb->nr_objects, 0, pb->progress_cb_payload)) {
-				giterr_clear();
-				return GIT_EUSER;
-			}
+
+			if (pb->progress_cb(
+					GIT_PACKBUILDER_ADDING_OBJECTS,
+					pb->nr_objects, 0, pb->progress_cb_payload))
+				return giterr_user_cancel();
 		}
 	}
 
@@ -1284,21 +1288,22 @@ const git_oid *git_packbuilder_hash(git_packbuilder *pb)
 	return &pb->pack_oid;
 }
 
-static int cb_tree_walk(const char *root, const git_tree_entry *entry, void *payload)
+static int cb_tree_walk(
+	const char *root, const git_tree_entry *entry, void *payload)
 {
+	int error;
 	struct tree_walk_context *ctx = payload;
 
 	/* A commit inside a tree represents a submodule commit and should be skipped. */
 	if (git_tree_entry_type(entry) == GIT_OBJ_COMMIT)
 		return 0;
 
-	if (git_buf_sets(&ctx->buf, root) < 0 ||
-		git_buf_puts(&ctx->buf, git_tree_entry_name(entry)) < 0)
-		return -1;
+	if (!(error = git_buf_sets(&ctx->buf, root)) &&
+		!(error = git_buf_puts(&ctx->buf, git_tree_entry_name(entry))))
+		error = git_packbuilder_insert(
+			ctx->pb, git_tree_entry_id(entry), git_buf_cstr(&ctx->buf));
 
-	return git_packbuilder_insert(ctx->pb,
-		git_tree_entry_id(entry),
-		git_buf_cstr(&ctx->buf));
+	return giterr_capture(&ctx->error, error);
 }
 
 int git_packbuilder_insert_commit(git_packbuilder *pb, const git_oid *oid)
@@ -1318,22 +1323,20 @@ int git_packbuilder_insert_commit(git_packbuilder *pb, const git_oid *oid)
 
 int git_packbuilder_insert_tree(git_packbuilder *pb, const git_oid *oid)
 {
-	git_tree *tree;
+	int error;
+	git_tree *tree = NULL;
 	struct tree_walk_context context = { pb, GIT_BUF_INIT };
 
-	if (git_tree_lookup(&tree, pb->repo, oid) < 0 ||
-	    git_packbuilder_insert(pb, oid, NULL) < 0)
-		return -1;
+	if (!(error = git_tree_lookup(&tree, pb->repo, oid)) &&
+	    !(error = git_packbuilder_insert(pb, oid, NULL)))
+		error = git_tree_walk(tree, GIT_TREEWALK_PRE, cb_tree_walk, &context);
 
-	if (git_tree_walk(tree, GIT_TREEWALK_PRE, cb_tree_walk, &context) < 0) {
-		git_tree_free(tree);
-		git_buf_free(&context.buf);
-		return -1;
-	}
+	if (error == GIT_EUSER)
+		error = giterr_restore(&context.error);
 
 	git_tree_free(tree);
 	git_buf_free(&context.buf);
-	return 0;
+	return error;
 }
 
 uint32_t git_packbuilder_object_count(git_packbuilder *pb)