static int apply_one()

in src/apply.c [440:581]

• 94 lines of code
• 27 McCabe index (conditional complexity)

static int apply_one(
	git_repository *repo,
	git_reader *preimage_reader,
	git_index *preimage,
	git_reader *postimage_reader,
	git_index *postimage,
	git_diff *diff,
	git_strmap *removed_paths,
	size_t i,
	const git_apply_options *opts)
{
	git_patch *patch = NULL;
	git_buf pre_contents = GIT_BUF_INIT, post_contents = GIT_BUF_INIT;
	const git_diff_delta *delta;
	char *filename = NULL;
	unsigned int mode;
	git_oid pre_id, post_id;
	git_filemode_t pre_filemode;
	git_index_entry pre_entry, post_entry;
	bool skip_preimage = false;
	int error;

	if ((error = git_patch_from_diff(&patch, diff, i)) < 0)
		goto done;

	delta = git_patch_get_delta(patch);

	if (opts->delta_cb) {
		error = opts->delta_cb(delta, opts->payload);

		if (error) {
			if (error > 0)
				error = 0;

			goto done;
		}
	}

	/*
	 * Ensure that the file has not been deleted or renamed if we're
	 * applying a modification delta.
	 */
	if (delta->status != GIT_DELTA_RENAMED &&
	    delta->status != GIT_DELTA_ADDED) {
		if (git_strmap_exists(removed_paths, delta->old_file.path)) {
			error = apply_err("path '%s' has been renamed or deleted", delta->old_file.path);
			goto done;
		}
	}

	/*
	 * We may be applying a second delta to an already seen file.  If so,
	 * use the already modified data in the postimage instead of the
	 * content from the index or working directory.  (Don't do this in
	 * the case of a rename, which must be specified before additional
	 * deltas since we apply deltas to the target filename.)
	 */
	if (delta->status != GIT_DELTA_RENAMED) {
		if ((error = git_reader_read(&pre_contents, &pre_id, &pre_filemode,
		    postimage_reader, delta->old_file.path)) == 0) {
			skip_preimage = true;
		} else if (error == GIT_ENOTFOUND) {
			git_error_clear();
			error = 0;
		} else {
			goto done;
		}
	}

	if (!skip_preimage && delta->status != GIT_DELTA_ADDED) {
		error = git_reader_read(&pre_contents, &pre_id, &pre_filemode,
			preimage_reader, delta->old_file.path);

		/* ENOTFOUND means the preimage was not found; apply failed. */
		if (error == GIT_ENOTFOUND)
			error = GIT_EAPPLYFAIL;

		/* When applying to BOTH, the index did not match the workdir. */
		if (error == GIT_READER_MISMATCH)
			error = apply_err("%s: does not match index", delta->old_file.path);

		if (error < 0)
			goto done;

		/*
		 * We need to populate the preimage data structure with the
		 * contents that we are using as the preimage for this file.
		 * This allows us to apply patches to files that have been
		 * modified in the working directory.  During checkout,
		 * we will use this expected preimage as the baseline, and
		 * limit checkout to only the paths affected by patch
		 * application.  (Without this, we would fail to write the
		 * postimage contents to any file that had been modified
		 * from HEAD on-disk, even if the patch application succeeded.)
		 * Use the contents from the delta where available - some
		 * fields may not be available, like the old file mode (eg in
		 * an exact rename situation) so trust the patch parsing to
		 * validate and use the preimage data in that case.
		 */
		if (preimage) {
			memset(&pre_entry, 0, sizeof(git_index_entry));
			pre_entry.path = delta->old_file.path;
			pre_entry.mode = delta->old_file.mode ? delta->old_file.mode : pre_filemode;
			git_oid_cpy(&pre_entry.id, &pre_id);

			if ((error = git_index_add(preimage, &pre_entry)) < 0)
				goto done;
		}
	}

	if (delta->status != GIT_DELTA_DELETED) {
		if ((error = git_apply__patch(&post_contents, &filename, &mode,
				pre_contents.ptr, pre_contents.size, patch, opts)) < 0 ||
			(error = git_blob_create_from_buffer(&post_id, repo,
				post_contents.ptr, post_contents.size)) < 0)
			goto done;

		memset(&post_entry, 0, sizeof(git_index_entry));
		post_entry.path = filename;
		post_entry.mode = mode;
		git_oid_cpy(&post_entry.id, &post_id);

		if ((error = git_index_add(postimage, &post_entry)) < 0)
			goto done;
	}

	if (delta->status == GIT_DELTA_RENAMED ||
	    delta->status == GIT_DELTA_DELETED)
		error = git_strmap_set(removed_paths, delta->old_file.path, (char *) delta->old_file.path);

	if (delta->status == GIT_DELTA_RENAMED ||
	    delta->status == GIT_DELTA_ADDED)
		git_strmap_delete(removed_paths, delta->new_file.path);

done:
	git_buf_dispose(&pre_contents);
	git_buf_dispose(&post_contents);
	git__free(filename);
	git_patch_free(patch);

	return error;
}