Re: PATCH: prompt truncation with multibyte characters

[Peter Stephenson <p.w.stephenson@ntlworld.com>]

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> I get both freezes and crashes with this code, I have a backtrace for
> a crash at the end of the mail. 
>..
> The difference being
> the one that crashes is one character longer. It also seems any name
> shorter than that works fine, and the ones longer crash, but i can't
> guarantee that. And yes, the short ones are still long enough to be
> truncated and seem to be so correctly.

Thanks.  It was some overenthusiastic moving of a string so that it
stuck off the end of the allocated area; as the allocated area was
initially 255 bytes it didnʼt happen until the string was roughly half
that.

I spotted one almost entirely irrelevant warning and two apparent
inconsistencies around print -P and print -D while I was doing this.

Index: Src/builtin.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/builtin.c,v
retrieving revision 1.149
diff -u -r1.149 builtin.c
--- Src/builtin.c	17 Sep 2005 18:23:50 -0000	1.149
+++ Src/builtin.c	19 Oct 2005 21:49:24 -0000
@@ -3368,7 +3368,7 @@
 	     */
 	    char *str = unmetafy(promptexpand(metafy(args[n], len[n],
 						     META_NOALLOC), 0, NULL, NULL), &len[n]);
-	    args[n] = dupstring(str);
+	    args[n] = dupstrpfx(str, len[n]);
 	    free(str);
 	}
 	/* -D option -- interpret as a directory, and use ~ */
@@ -3378,9 +3378,9 @@
 	    queue_signals();
 	    d = finddir(args[n]);
 	    if(d) {
-		char *arg = zhalloc(strlen(args[n]) + 1);
-		sprintf(arg, "~%s%s", d->nam,
-			args[n] + strlen(d->dir));
+		int dirlen = strlen(d->dir);
+		char *arg = zhalloc(len[n] - dirlen + strlen(d->nam) + 2);
+		sprintf(arg, "~%s%s", d->nam, args[n] + dirlen);
 		args[n] = arg;
 		len[n] = strlen(args[n]);
 	    }
Index: Src/prompt.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/prompt.c,v
retrieving revision 1.27
diff -u -r1.27 prompt.c
--- Src/prompt.c	19 Oct 2005 08:39:03 -0000	1.27
+++ Src/prompt.c	19 Oct 2005 21:49:25 -0000
@@ -1078,7 +1078,7 @@
 		    int remw;
 		    mbstate_t mbs;
 
-		    fulltextptr = fulltext = bp;
+		    fulltextptr = fulltext = ptr + ntrunc;
 		    memmove(fulltext, ptr, fullen);
 		    fulltext[fullen] = '\0';
 
Index: Src/Zle/zle_utils.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/Zle/zle_utils.c,v
retrieving revision 1.28
diff -u -r1.28 zle_utils.c
--- Src/Zle/zle_utils.c	29 Sep 2005 17:32:38 -0000	1.28
+++ Src/Zle/zle_utils.c	19 Oct 2005 21:49:25 -0000
@@ -787,7 +787,8 @@
     ZLE_CHAR_T c;
 #ifdef ZLE_UNICODE_SUPPORT
     char *umsg;
-    int ulen, ret, width;
+    int ulen, ret;
+    size_t width;
     mbstate_t ps;
 #endif
 
-- 
Peter Stephenson <p.w.stephenson@ntlworld.com>
Web page still at http://www.pwstephenson.fsnet.co.uk/