On Thu, Feb 3, 2022 at 1:04 AM Elijah Newren <newren@xxxxxxxxx> wrote: > > On Wed, Feb 2, 2022 at 6:09 PM Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> wrote: > > > > On Wed, Feb 02 2022, Elijah Newren via GitGitGadget wrote: > > > > > From: Elijah Newren <newren@xxxxxxxxx> > > > > > > Let merge-tree accept a `--write-tree` parameter for choosing real > > > merges instead of trivial merges, and accept an optional > > > `--trivial-merge` option to get the traditional behavior. Note that > > > these accept different numbers of arguments, though, so these names > > > need not actually be used. > > > > Maybe that ship has sailed, but just my 0.02: I thought this whole thing > > was much less confusing with your initial merge-tree-ort proposal at > > https://lore.kernel.org/git/CABPp-BEeBpJoU4yXdfA6vRAYVAUbd2gRhEV6j4VEqoqcu=FGSw@xxxxxxxxxxxxxx/; > > I.e. the end-state of merge-tree.c is that you end up reading largely > > unrelated code (various static functions only used by one side or > > another). > > Christian's merge-tree-ort proposal? > > > But maybe that's all water under the bridge etc, however... > > > > > 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'), > > > + 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'); > > > + } > > > > Do we really need to make this interface more special-casey by > > auto-guessing based on argc what argument you want? I.e. instead of > > usage like: > > > > N_("git merge-tree [--write-tree] <branch1> <branch2>"), > > N_("git merge-tree [--trivial-merge] <base-tree> <branch1> <branch2>"), > > > > Wouldn't it be simpler to just have the equivalent of: > > > > # old > > git merge-tree ... > > # new > > git merge-tree --new-thing ... > > > > And not have to look at ... to figure out if we're dispatching to the > > new or old thing. > > You seem to be focusing on code simplicity? Sure, that'd be simpler > code, it'd just be a less useful feature. > > I think passing --write-tree all the time would be an annoyance. I > don't see why anyone would ever use the other mode. However, for as > long as both exist in the manual, it makes the manual easier to > explain to users, and example testcases more self-documenting by > having the flag there. That's the sole purpose of the flag. > > I'm never going to actually use it when I invoke it from the command > line. And I suspect most would leave it off. ...also, even if we did require the `--write-tree` flag, we'd still have to look at argc. Since the option parsing handles both modes, someone could leave off --write-tree, but include a bunch of other options that only make sense with --write-tree. Individually checking the setting of every extra flag along with write_tree is a royal pain and I don't want to repeat that for each new option added. Simply checking argc allows you to provide an error message if the user does that. (And I think it's sad that in Git we often forgot to warn and notify users of options that are only functional with certain other arguments; it makes it harder for users to figure out, and has in the past even made it harder for other developers to figure out what was meant and how things are to be used. I think I've seen multiple Git devs be confused over ls-files --directory and --no-empty-directory options, assuming they'd do something sensible for tracked files, when in fact those arguments are simply ignored because they are only modifiers for how untracked files are treated.)
