Re: [PATCH v2 2/2] add-patch: do not print hunks repeatedly

["Rubén Justo" <rjusto@gmail.com>]

On Tue, Mar 26, 2024 at 02:39:18PM +0000, Phillip Wood wrote:

> >      $ git add -p
> >      diff --git a/add-patch.c b/add-patch.c
> >      index 52be1ddb15..8fb75e82e2 100644
> >      --- a/add-patch.c
> >      +++ b/add-patch.c
> >      @@ -1394,7 +1394,7 @@ N_("j - leave this hunk undecided, see next undecided hunk\n"
> >       static int patch_update_file(struct add_p_state *s,
> >       			     struct file_diff *file_diff)
> >       {
> >      -	size_t hunk_index = 0;
> >      +	size_t hunk_index = 0, prev_hunk_index = -1;
> >       	ssize_t i, undecided_previous, undecided_next;
> >       	struct hunk *hunk;
> >       	char ch;
> >      (1/4) Stage this hunk [y,n,q,a,d,j,J,g,/,e,p,?]? U
> >      y - stage this hunk
> >      n - do not stage this hunk
> >      q - quit; do not stage this hunk or any of the remaining ones
> >      a - stage this hunk and all later hunks in the file
> >      d - do not stage this hunk or any of the later hunks in the file
> >      j - leave this hunk undecided, see next undecided hunk
> >      J - leave this hunk undecided, see next hunk
> >      g - select a hunk to go to
> >      / - search for a hunk matching the given regex
> >      e - manually edit the current hunk
> >      p - print again the current hunk
> >      ? - print help
> >      @@ -1394,7 +1394,7 @@ N_("j - leave this hunk undecided, see next undecided hunk\n"
> >       static int patch_update_file(struct add_p_state *s,
> >       			     struct file_diff *file_diff)
> >       {
> >      -	size_t hunk_index = 0;
> >      +	size_t hunk_index = 0, prev_hunk_index = -1;
> >       	ssize_t i, undecided_previous, undecided_next;
> >       	struct hunk *hunk;
> >       	char ch;
> >      (1/4) Stage this hunk [y,n,q,a,d,j,J,g,/,e,p,?]?
> > 
> > Printing the chunk again followed by the question can be confusing as
> > the user has to pay special attention to notice that the same chunk is
> > being reconsidered.
> 
> As we print a long help message if we don't re-display the hunk it ends up
> being separated from the prompt. Personally I find the help message quite
> annoying when I've fat-fingered the wrong key - I'd prefer a shorter message
> pointing to "?" to display more help. We already do something similar if the
> user presses a key such as "s" that is disabled for the current hunk.

Yeah, I would like that too.  Maybe something like:

     $ git add -p
     diff --git a/add-patch.c b/add-patch.c
     index 52be1ddb15..8fb75e82e2 100644
     --- a/add-patch.c
     +++ b/add-patch.c
     @@ -1394,7 +1394,7 @@ N_("j - leave this hunk undecided, see next undecided hunk\n"
      static int patch_update_file(struct add_p_state *s,
      			     struct file_diff *file_diff)
      {
     -	size_t hunk_index = 0;
     +	size_t hunk_index = 0, prev_hunk_index = -1;
      	ssize_t i, undecided_previous, undecided_next;
      	struct hunk *hunk;
      	char ch;
     (1/4) Stage this hunk [y,n,q,a,d,j,J,g,/,e,p,?]? U
     Unknown option "U".  Use '?' for help.
     (1/4) Stage this hunk [y,n,q,a,d,j,J,g,/,e,p,?]? 


I think such a change fits well in this series.  Let's see if it does.

> > -	size_t hunk_index = 0;
> > +	size_t hunk_index = 0, prev_hunk_index = -1;
> 
> I found the name a bit confusing as we have keys for displaying the previous
> hunk and it make me think of that. As it is used to record the index of the
> hunk that we've rendered perhaps "rendered_hunk_index" would be a better
> name.

OK.

> Also as it needs to hold a negative value we should declare it as
> ssize_t like the variables on the line below.

Very good point.  OK.

> 
> >   	ssize_t i, undecided_previous, undecided_next;
> >   	struct hunk *hunk;
> >   	char ch;
> > @@ -1448,10 +1448,14 @@ static int patch_update_file(struct add_p_state *s,
> >   		strbuf_reset(&s->buf);
> >   		if (file_diff->hunk_nr) {
> > -			render_hunk(s, hunk, 0, colored, &s->buf);
> > -			fputs(s->buf.buf, stdout);
> > +			if (prev_hunk_index != hunk_index) {
> > +				render_hunk(s, hunk, 0, colored, &s->buf);
> > +				fputs(s->buf.buf, stdout);
> > +				strbuf_reset(&s->buf);
> > +
> > +				prev_hunk_index = hunk_index;
> > +			}
> > -			strbuf_reset(&s->buf);
> 
> I'd be inclined to leave this line as is to make it clear that the strbuf is
> always cleared before adding the keybindings.

If find having two strbuf_reset()'s in a row confusing.  Maybe it is
just me not seeing that that second strbuf_reset is "close" to noop.

> 
> >   			if (undecided_previous >= 0) {
> >   				permitted |= ALLOW_GOTO_PREVIOUS_UNDECIDED_HUNK;
> >   				strbuf_addstr(&s->buf, ",k");
> > @@ -1649,10 +1653,12 @@ static int patch_update_file(struct add_p_state *s,
> >   			if (!(permitted & ALLOW_SPLIT))
> 
> style: as you're adding braces to the other clause in this if statement you
> should add them to this clause as well.

OK