Re: Problem with completion matching control

[Sven Wischnowsky <wischnow@xxxxxxxxxxxxxxxxxxxxxxx>]

Oliver Kiddle wrote:

> There seems to be a few problems with the completeinword option though.
> Could someone offer a better explanation of what completeinword does
> than the documentation gives. I think that when I first configured zsh,
> I assumed that it allowed zsh to be more intelligent when completing
> with the cursor in the middle of the line so I set it.

With completeinword set the code splits the string on the line into a
prefix (before the cursor) and a suffix (after the cursor). Then it
generates the completions as usual, but it accepts only those strings
that have the prefix *and* the suffix from the line. I.e. with the
string `ab' and the cursor between the to only word beginning with `a' 
and ending with `b' are accepted.

> With autocd and completeinword set and the compctl MATCH 'm:{a-z}={A-Z}'
> from the zsh source directory, if I type 
> ./co<tab>
> I get completion working but it gets stuck on ./Config/. Is this a bug
> or what is intended by completeinword.

This was an ugly interaction between completeinword, listambiguous,
and automenu, actually. With listambiguous one more TAB is needed to
start menucompletion. But on the second TAB the cursor was moved into
the word, after the `c' to allow easy editing of the ambiguous
place. Without listambiguous menucompletion would now have been
started instead. But with listambiguous the next TAB made the code
search for a match beginning with `./c' and ending with `onfig' -- and 
there was only one such possible completion, the directory `Config'.
In a certain sense this was correct behavior. What made this
unacceptable was that there were no way to start automenu in such a
case. The patch below makes the code remember if it moved the cursor
into the word itself and restore the cursor to its old position before 
the next completion if that is the case.

> I also tested out your fix for the matching control which prevents *
> mapping to the anchor so ncftp sunsite.d<tab> works as I had wanted. I
> found the following which I think is a bug:
> 
> zsh -f
> setopt completeinword
> compctl -x 'p[1]' -k '(a.b.c a.c.b)' -M 'r:|.=*  r:|=*' -- t
> t a.<tab><tab><tab>
> 
> The above will complete to a.b.c, having never listed the alternatives.
> It works as I would expect when completeinword is not set.
> 
> I also get the following which is certainly worse:
> 
> First three commands same as above
> t a..c<left><left><tab>
> Gives me: zsh: 4013 segmentation fault
> With completeinword unsetopted, this works fine.

The first one is fixed by the patch below, too. The second one should
be fixed by the patch I sent yesterday.

Maybe noone understands me when I'm talking about the internals of the 
completion code, but still: these were caused by the current state of
the function join_clines(). The completion code builds lists of cline
structs to describe what should be put into the command line for each 
of the matches (actually, only for the complicated matches for which
match specs were used). After building such a list, join_clines() is
called to simplify the already existing cline list for the previous
matches so that it also adequately describes the new match. Most of
this function still comes from the days when we didn't have the new
completion code, the (big) patches from yesterday and last week
slightly improved it, but I still have to go through it once
more. This will then be my last change to the older completion code
apart from bug fixes for quite some time.
(You may now say that you didn't use the new completion stuff in the
example above -- you triggered a small error with setting flags in the 
cline struct that described the middle part of the string to insert,
the part where the prefix and the suffix meet).

Bye
 Sven

diff -u os/Zle/comp.h Src/Zle/comp.h
--- os/Zle/comp.h	Mon Feb 22 13:38:45 1999
+++ Src/Zle/comp.h	Tue Feb 23 09:02:31 1999
@@ -271,9 +271,10 @@
 #define CLF_MISS   4
 #define CLF_DIFF   8
 #define CLF_SUF   16
-#define CLF_NEW   32
-#define CLF_VAR   64
-#define CLF_JOIN 128
+#define CLF_PNEW  32
+#define CLF_SNEW  64
+#define CLF_VAR  128
+#define CLF_JOIN 256
 
 /* Flags for makecomplist*(). Things not to do. */
 
diff -u os/Zle/zle_tricky.c Src/Zle/zle_tricky.c
--- os/Zle/zle_tricky.c	Mon Feb 22 13:38:47 1999
+++ Src/Zle/zle_tricky.c	Tue Feb 23 10:39:28 1999
@@ -291,12 +291,24 @@
 
 static int lastambig;
 
-/* Non-zero if the string on the line came from a previous completion. *
- * This is used to detect if the string should be taken as an exact    *
- * match (see do_ambiguous()).                                         */
+/* This says what of the state the line is in when completion is started *
+ * came from a previous completion. If the FC_LINE bit is set, the       *
+ * string was inserted. If FC_INWORD is set, the last completion moved   *
+ * the cursor into the word although it was at the end of it when the    *
+ * last completion was invoked.                                          *
+ * This is used to detect if the string should be taken as an exact      *
+ * match (see do_ambiguous()) and if the cursor has to be moved to the   *
+ * end of the word before generating the completions.                    */
 
 static int fromcomp;
 
+/* This holds the end-position of the last string inserted into the line. */
+
+static int lastend;
+
+#define FC_LINE   1
+#define FC_INWORD 2
+
 /**/
 void
 completecall(void)
@@ -605,6 +617,12 @@
 	return;
     }
 
+    /* We may have to reset the cursor to its position after the   *
+     * string inserted by the last completion. */
+
+    if (fromcomp & FC_INWORD)
+	cs = lastend;
+
     /* Check if we have to start a menu-completion (via automenu). */
 
     if ((amenu = (isset(AUTOMENU) && lastambig &&
@@ -2346,7 +2364,7 @@
 	*olp = 0;
     if (nlp)
 	*nlp = 0;
-    if (o->flags & CLF_NEW) {
+    if (o->flags & CLF_PNEW) {
 	if (o->flags & (CLF_END | CLF_MID))
 	    /* We split the suffix in the middle and at the end into
 	     * separate runs. */
@@ -2363,7 +2381,7 @@
 		o->flags |= CLF_MISS;
 	}
     } else if (o->flags & (CLF_END | CLF_MID)) {
-	o->flags |= CLF_NEW;
+	o->flags |= CLF_PNEW;
 	o->prefix = join_ends(end_list(o->wlen, o->word),
 			      end_list(n->wlen, n->word), olp, nlp);
     } else if (o->wlen && n->wlen) {
@@ -2388,7 +2406,7 @@
 	     * matches both strings from the original cline structs
 	     * and thus can be put in the command line to represent
 	     * them. This cline list is stored in o. */
-	    o->flags |= CLF_NEW;
+	    o->flags |= CLF_PNEW;
 	    o->prefix = bld_new_pfx(o->wlen, o->word, n->wlen, n->word,
 				    &mol, &mnl, NULL);
 	    newl = 0;
@@ -2769,7 +2787,7 @@
 static void
 bld_sfx(Cline o, Cline n)
 {
-    if (o->flags & CLF_NEW) {
+    if (o->flags & CLF_SNEW) {
 	int miss;
 
 	o->suffix = join_new_sfx(o->suffix, n->wlen, n->word, &miss);
@@ -2785,7 +2803,7 @@
 	    new = dupstring(n->word);
 	    newl = n->wlen;
 	} else if (!strpfx(o->word, n->word)) {
-	    o->flags |= CLF_NEW;
+	    o->flags |= CLF_SNEW;
 	    o->suffix = bld_new_sfx(o->wlen, o->word, n->wlen, n->word,
 				    &mol, &mnl, NULL);
 	    newl = 0;
@@ -3234,6 +3252,7 @@
 	}
 	l = l->next;
     }
+    lastend = cs;
     /* Now place the cursor. Preferably in a position where something
      * is missing, otherwise in a place where the string differs from
      * any of the matches, or just leave it at the end. */
@@ -3873,6 +3892,7 @@
 	inststrlen(m->suf, 1, (l = strlen(m->suf)));
 	r += l;
     }
+    lastend = cs;
     cs = ocs;
     return r;
 }
@@ -6999,7 +7019,7 @@
     /* If we have to insert the first match, call do_single().  This is *
      * how REC_EXACT takes effect.  We effectively turn the ambiguous   *
      * completion into an unambiguous one.                              */
-    if (ainfo && ainfo->exact == 1 && isset(RECEXACT) && !fromcomp &&
+    if (ainfo && ainfo->exact == 1 && isset(RECEXACT) && !(fromcomp & FC_LINE) &&
 	(usemenu == 0 || unset(AUTOMENU))) {
 	do_single(ainfo->exactm);
 	invalidatelist();
@@ -7072,7 +7092,6 @@
 		    merge_cline(lc, ps, lp, NULL, 0, 0);
 	    }
 	    inst_cline(lc, pl, sl);
-
 	} else {
 	    inststrlen(ps, 1, -1);
 	    ocs = cs;
@@ -7093,6 +7112,7 @@
 		cs -= brsl;
 		inststrlen(brend, 1, -1);
 	    }
+	    lastend = cs;
 	    cs = ocs;
 	}
 	/* la is non-zero if listambiguous may be used. Copying and
@@ -7100,11 +7120,13 @@
 	 * solution. Really. */
 	la = (ll != oll || strncmp(oline, (char *) line, ll));
 
-	/* If REC_EXACT and AUTO_MENU are set and what we inserted is an *
-	 * exact match, we want menu completion the next time round      *
-	 * so we set fromcomp,to ensure that the word on the line is not *
-	 * taken as an exact match.                                      */
-	fromcomp = isset(AUTOMENU);
+	/* If REC_EXACT and AUTO_MENU are set and what we inserted is an  *
+	 * exact match, we want menu completion the next time round       *
+	 * so we set fromcomp,to ensure that the word on the line is not  *
+	 * taken as an exact match. Also we remember if we just moved the *
+	 * cursor into the word.                                          */
+	fromcomp = ((isset(AUTOMENU) ? FC_LINE : 0) |
+		    ((atend && cs != lastend) ? FC_INWORD : 0));
 
 	/*
 	 * If the LIST_AMBIGUOUS option (meaning roughly `show a list only *

--
Sven Wischnowsky                         wischnow@xxxxxxxxxxxxxxxxxxxxxxx