"Elijah Newren via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes: > +struct merge_tree_options { > + int mode; > +}; > +static int real_merge(struct merge_tree_options *o, > + const char *branch1, const char *branch2) > +{ > + die(_("real merges are not yet implemented")); > +} > + > int cmd_merge_tree(int argc, const char **argv, const char *prefix) > { > - if (argc != 4) > - usage(merge_tree_usage); > - return trivial_merge(argc, argv); > + struct merge_tree_options o = { 0 }; > + int expected_remaining_argc; > + > + const char * const merge_tree_usage[] = { > + N_("git merge-tree [--write-tree] <branch1> <branch2>"), > + N_("git merge-tree [--trivial-merge] <base-tree> <branch1> <branch2>"), > + NULL > + }; > + struct option mt_options[] = { > + OPT_CMDMODE(0, "write-tree", &o.mode, > + N_("do a real merge instead of a trivial merge"), > + 'w'), Given the length of the second line in the usage[] array, it would make more sense to have "'w')," on the same line to make it match better with the following one. > + OPT_CMDMODE(0, "trivial-merge", &o.mode, > + N_("do a trivial merge only"), 't'), > + OPT_END() > + }; > + > + /* Parse arguments */ > + argc = parse_options(argc, argv, prefix, mt_options, > + merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION); > + if (o.mode) { > + expected_remaining_argc = (o.mode == 'w' ? 2 : 3); > + if (argc != expected_remaining_argc) > + usage_with_options(merge_tree_usage, mt_options); > + } else { > + if (argc < 2 || argc > 3) > + usage_with_options(merge_tree_usage, mt_options); > + o.mode = (argc == 2 ? 'w' : 't'); > + } We are not planning to have tons of different command modes, but the above looks quite brittle in assuming that 'w' and 't' are the only ones, and not having an easy way to extend the part without major rewrite when the assumption will have to be broken. I wonder: switch (o.cmd_mode) { default: BUG("unexpected cmdmode %c", o.cmd_mode); case 0: switch (argc) { default: usage_with_options(merge_tree_usage, mt_options); case 2: o.cmd_mode = 'w'; break; case 3: o.cmd_mode = 't'; break; } expected_remaining_argc = argc; break; case 'w': expected_remaining_argc = 2; break; case 't': expected_remaining_argc = 3; break; } if (argc != expected_remaining_argc) usage_with_options(merge_tree_usage, mt_options); even though it is a tad longer with more boilerplate, is easlier to manage. > + /* Do the relevant type of merge */ > + if (o.mode == 'w') > + return real_merge(&o, argv[0], argv[1]); > + else > + return trivial_merge(argv[0], argv[1], argv[2]); > } > diff --git a/git.c b/git.c > index 5ff21be21f3..6090a1289db 100644 > --- a/git.c > +++ b/git.c > @@ -558,7 +558,7 @@ static struct cmd_struct commands[] = { > { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT }, > { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT }, > { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT }, > - { "merge-tree", cmd_merge_tree, RUN_SETUP | NO_PARSEOPT }, > + { "merge-tree", cmd_merge_tree, RUN_SETUP }, This affects git_support_parseopt_helper function in the completion script, but it by itself is very unlikely to break existing tests on the completion, as the bit only affects how the command line options are completed, and the command didn't have any command line options to be tested before this series ;-) > { "mktag", cmd_mktag, RUN_SETUP | NO_PARSEOPT }, > { "mktree", cmd_mktree, RUN_SETUP }, > { "multi-pack-index", cmd_multi_pack_index, RUN_SETUP },