Re: [PATCH 1/1] rebase: deprecate --preserve-merges

[Phillip Wood <phillip.wood123@gmail.com>]

Hi Johannes

It's great to see this. Do we need the deprecation warning in both 
builtin/rebase.c and rebase--preserve-merges.sh? Won't that end up 
warning twice - maybe that's a good thing but if we go for only one I 
prefer the wording in rebase--preserve-merges.sh

Best Wishes

Phillip

On 07/03/2019 10:00, Johannes Schindelin via GitGitGadget wrote:
> From: Johannes Schindelin <johannes.schindelin@gmx.de>
> 
> We have something much better now: --rebase-merges (which is a
> complete re-design --preserve-merges, with a lot of issues fixed such as
> the inability to reorder commits with --preserve-merges).
> 
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>   Documentation/config/branch.txt |  6 +++---
>   Documentation/config/pull.txt   |  6 +++---
>   Documentation/git-rebase.txt    | 23 ++++++++++++-----------
>   builtin/rebase.c                |  8 ++++++--
>   git-rebase--preserve-merges.sh  |  2 ++
>   5 files changed, 26 insertions(+), 19 deletions(-)
> 
> diff --git a/Documentation/config/branch.txt b/Documentation/config/branch.txt
> index 019d60ede2..8f4b3faadd 100644
> --- a/Documentation/config/branch.txt
> +++ b/Documentation/config/branch.txt
> @@ -85,9 +85,9 @@ When `merges`, pass the `--rebase-merges` option to 'git rebase'
>   so that the local merge commits are included in the rebase (see
>   linkgit:git-rebase[1] for details).
>   +
> -When preserve, also pass `--preserve-merges` along to 'git rebase'
> -so that locally committed merge commits will not be flattened
> -by running 'git pull'.
> +When `preserve` (deprecated in favor of `merges`), also pass
> +`--preserve-merges` along to 'git rebase' so that locally committed merge
> +commits will not be flattened by running 'git pull'.
>   +
>   When the value is `interactive`, the rebase is run in interactive mode.
>   +
> diff --git a/Documentation/config/pull.txt b/Documentation/config/pull.txt
> index bb23a9947d..b87cab31b3 100644
> --- a/Documentation/config/pull.txt
> +++ b/Documentation/config/pull.txt
> @@ -18,9 +18,9 @@ When `merges`, pass the `--rebase-merges` option to 'git rebase'
>   so that the local merge commits are included in the rebase (see
>   linkgit:git-rebase[1] for details).
>   +
> -When preserve, also pass `--preserve-merges` along to 'git rebase'
> -so that locally committed merge commits will not be flattened
> -by running 'git pull'.
> +When `preserve` (deprecated in favor of `merges`), also pass
> +`--preserve-merges` along to 'git rebase' so that locally committed merge
> +commits will not be flattened by running 'git pull'.
>   +
>   When the value is `interactive`, the rebase is run in interactive mode.
>   +
> diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
> index 5629ba4c5d..89202dbb93 100644
> --- a/Documentation/git-rebase.txt
> +++ b/Documentation/git-rebase.txt
> @@ -415,9 +415,9 @@ i.e. commits that would be excluded by gitlink:git-log[1]'s
>   the `rebase-cousins` mode is turned on, such commits are instead rebased
>   onto `<upstream>` (or `<onto>`, if specified).
>   +
> -The `--rebase-merges` mode is similar in spirit to `--preserve-merges`, but
> -in contrast to that option works well in interactive rebases: commits can be
> -reordered, inserted and dropped at will.
> +The `--rebase-merges` mode is similar in spirit to the deprecated
> +`--preserve-merges`, but in contrast to that option works well in interactive
> +rebases: commits can be reordered, inserted and dropped at will.
>   +
>   It is currently only possible to recreate the merge commits using the
>   `recursive` merge strategy; Different merge strategies can be used only via
> @@ -427,9 +427,10 @@ See also REBASING MERGES and INCOMPATIBLE OPTIONS below.
>   
>   -p::
>   --preserve-merges::
> -	Recreate merge commits instead of flattening the history by replaying
> -	commits a merge commit introduces. Merge conflict resolutions or manual
> -	amendments to merge commits are not preserved.
> +	[DEPRECATED: use --rebase-merges instead] Recreate merge commits
> +	instead of flattening the history by replaying commits a merge commit
> +	introduces. Merge conflict resolutions or manual amendments to merge
> +	commits are not preserved.
>   +
>   This uses the `--interactive` machinery internally, but combining it
>   with the `--interactive` option explicitly is generally not a good
> @@ -1020,11 +1021,11 @@ merge cmake
>   
>   BUGS
>   ----
> -The todo list presented by `--preserve-merges --interactive` does not
> -represent the topology of the revision graph.  Editing commits and
> -rewording their commit messages should work fine, but attempts to
> -reorder commits tend to produce counterintuitive results. Use
> -`--rebase-merges` in such scenarios instead.
> +The todo list presented by the deprecated `--preserve-merges --interactive`
> +does not represent the topology of the revision graph (use `--rebase-merges`
> +instead).  Editing commits and rewording their commit messages should work
> +fine, but attempts to reorder commits tend to produce counterintuitive results.
> +Use `--rebase-merges` in such scenarios instead.
>   
>   For example, an attempt to rearrange
>   ------------
> diff --git a/builtin/rebase.c b/builtin/rebase.c
> index 7c7bc13e91..c5f5edf321 100644
> --- a/builtin/rebase.c
> +++ b/builtin/rebase.c
> @@ -1092,8 +1092,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>   			PARSE_OPT_NOARG | PARSE_OPT_NONEG,
>   			parse_opt_interactive },
>   		OPT_SET_INT('p', "preserve-merges", &options.type,
> -			    N_("try to recreate merges instead of ignoring "
> -			       "them"), REBASE_PRESERVE_MERGES),
> +			    N_("(DEPRECATED) try to recreate merges instead of "
> +			       "ignoring them"), REBASE_PRESERVE_MERGES),
>   		OPT_BOOL(0, "rerere-autoupdate",
>   			 &options.allow_rerere_autoupdate,
>   			 N_("allow rerere to update index with resolved "
> @@ -1204,6 +1204,10 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>   		usage_with_options(builtin_rebase_usage,
>   				   builtin_rebase_options);
>   
> +	if (options.type == REBASE_PRESERVE_MERGES)
> +		warning(_("--preserve-merges is deprecated in favor of "
> +			  "--rebase-merges"));
> +
>   	if (action != NO_ACTION && !in_progress)
>   		die(_("No rebase in progress?"));
>   	setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
> diff --git a/git-rebase--preserve-merges.sh b/git-rebase--preserve-merges.sh
> index afbb65765d..eab2e40dc6 100644
> --- a/git-rebase--preserve-merges.sh
> +++ b/git-rebase--preserve-merges.sh
> @@ -105,6 +105,8 @@ warn () {
>   	printf '%s\n' "$*" >&2
>   }
>   
> +warn "git rebase --preserve-merges is deprecated. Use --rebase-merges instead."
> +
>   # Output the commit message for the specified commit.
>   commit_message () {
>   	git cat-file commit "$1" | sed "1,/^$/d"
>