Re: vi-backward-kill-word

[Peter Stephenson <pws@csr.com>]

On Tue, 22 Apr 2008 01:10:40 +0900
"Jun T." <takimoto-j@kba.biglobe.ne.jp> wrote:
> Since you wrote in your first post:
>  >Known gaps at the moment:
>  >- Word tests need improving (a whole smattering HEREs)
>  >- Vi "r" needs some work (another HERE)
> 
> I guess you already know that vi "r" and "R" do not work properly
> on combined character(s).

I would have if I'd thought about it.  The problem with R was actually
generic to overstrike (non-insert) mode.  I think there's still a problem
in overstrike mode when you enter a combining character; it'll advance too
far right.  I'll look at that separately.

It's still the case that you can't use r and R with characters with
combining characters as arguments.  That's quite tough, since you don't
know they're are going to be any to read after the base character when
reading from the terminal.  We could use a timeout, I suppose, but even
so it would need a whole new layer of character input.

> Another minor problem is, when  in vi-insert mode, ^W
> (vi-backward-kill-word) kills wrong part of the line if the word
> to be killed contains combined character.
>...
> It *seems* it can be fixed by replacing the line 44 of zle_word.c
>      backkill(zlecs - x, CUT_FRONT);
> by
>      backkill(zlecs - x, CUT_FRONT|CUT_RAW);

Yep, that looks right... the CUT_RAW is needed any time the first argument
is a number of raw characters in the buffer, which it must be if it's
a difference of positions.  In fact, CUT_RAW should really be the default
because there are only very few places where the number comes directly from
the user where it isn't wanted.

I also found that vi-put-after (p) wasn't working for the usual reason to
do with character positions.

> # I guess you are busy working on many problems.
> # I fear I'm disturbing you...

Actually, I'd quite like to get the combining characters sorted out as soon
as possible.

Index: Src/Zle/zle_misc.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/Zle/zle_misc.c,v
retrieving revision 1.49
diff -u -r1.49 zle_misc.c
--- Src/Zle/zle_misc.c	20 Apr 2008 21:23:14 -0000	1.49
+++ Src/Zle/zle_misc.c	21 Apr 2008 17:19:56 -0000
@@ -47,14 +47,27 @@
     iremovesuffix(c1, 0);
     invalidatelist();
 
-    if(insmode)
+    if (insmode)
 	spaceinline(m * len);
-    else if(zlecs + m * len > zlell)
-	spaceinline(zlecs + m * len - zlell);
-    while(m--)
+    else {
+	int pos = zlecs, count = m * len, i = count, diff;
+	/*
+	 * Ensure we replace a complete combining character
+	 * for each character we overwrite.
+	 */
+	while (pos < zlell && i--) {
+	    INCPOS(pos);
+	}
+	diff = pos - zlecs - count;
+	if (diff < 0) {
+	    spaceinline(-diff);
+	} else if (diff > 0)
+	    foredel(diff, CUT_RAW);
+    }
+    while (m--)
 	for(s = zstr, count = len; count; s++, count--)
 	    zleline[zlecs++] = *s;
-    if(neg)
+    if (neg)
 	zlecs += zmult * len;
     /* if we ended up on a combining character, skip over it */
     CCRIGHT();
Index: Src/Zle/zle_vi.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/Zle/zle_vi.c,v
retrieving revision 1.19
diff -u -r1.19 zle_vi.c
--- Src/Zle/zle_vi.c	20 Apr 2008 21:17:30 -0000	1.19
+++ Src/Zle/zle_vi.c	21 Apr 2008 17:19:59 -0000
@@ -498,18 +498,19 @@
 vireplacechars(UNUSED(char **args))
 {
     ZLE_INT_T ch;
-    int n = zmult, origcs = zlecs, fail = 0;
+    int n = zmult, fail = 0, newchars = 0;
 
     if (n > 0) {
+	int pos = zlecs;
 	while (n-- > 0) {
-	    if (zlecs == zlell || zleline[zlell] == ZWC('\n')) {
+	    if (pos == zlell || zleline[pos] == ZWC('\n')) {
 		fail = 1;
 		break;
 	    }
-	    INCCS();
+	    newchars++;
+	    INCPOS(pos);
 	}
-	n = zlecs - origcs;
-	zlecs = origcs;
+	n = pos - zlecs;
     }
     startvichange(1);
     /* check argument range */
@@ -535,8 +536,16 @@
 	backkill(n - 1, CUT_RAW);
 	zleline[zlecs++] = '\n';
     } else {
-	/* HERE: we shouldn't replace combining chars, we should delete them */
-	while (n--)
+	/*
+	 * Make sure we delete displayed characters, including
+	 * attach combining characters. n includes this as a raw
+	 * buffer offset.
+	 */
+	if (n > newchars)
+	    foredel(n - newchars, CUT_RAW);
+	else if (n < newchars)
+	    spaceinline(newchars - n);
+	while (newchars--)
 	    zleline[zlecs++] = ch;
 	zlecs--;
     }
@@ -792,14 +801,14 @@
 	vifirstnonblank(zlenoargs);
     } else {
 	if (zlecs != findeol())
-	    zlecs++;
+	    INCCS();
 	while (n--) {
 	    spaceinline(buf->len);
 	    ZS_memcpy(zleline + zlecs, buf->buf, buf->len);
 	    zlecs += buf->len;
 	}
 	if (zlecs)
-	    zlecs--;
+	    DECCS();
     }
     return 0;
 }
Index: Src/Zle/zle_word.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/Zle/zle_word.c,v
retrieving revision 1.13
diff -u -r1.13 zle_word.c
--- Src/Zle/zle_word.c	20 Apr 2008 21:17:30 -0000	1.13
+++ Src/Zle/zle_word.c	21 Apr 2008 17:20:00 -0000
@@ -441,7 +441,7 @@
 	    }
 	}
     }
-    backkill(zlecs - x, CUT_FRONT);
+    backkill(zlecs - x, CUT_FRONT|CUT_RAW);
     return 0;
 }
 
@@ -475,7 +475,7 @@
 	    x = pos;
 	}
     }
-    backkill(zlecs - x, CUT_FRONT);
+    backkill(zlecs - x, CUT_FRONT|CUT_RAW);
     return 0;
 }
 
-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR PLC, Churchill House, Cambridge Business Park, Cowley Road
Cambridge, CB4 0WZ, UK                          Tel: +44 (0)1223 692070