Fix more fallout from line-wrap patch, to wit, arbitrarily changing

the API of PQdsplen without bothering to fix its callers.  Although
ReportSyntaxErrorPosition could probably do with more smarts about
handling control characters, for the moment I'll just get it back to
handling tabs consistently.

src/bin/psql/common.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2005, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/common.c,v 1.111 2005/11/22 18:17:29 momjian Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/common.c,v 1.112 2006/02/12 03:30:21 tgl Exp $
  */
 #include "postgres_fe.h"
 #include "common.h"
@@ -444,6 +444,7 @@ ReportSyntaxErrorPosition(const PGresult *result, const char *query)
 	int			clen,
 				slen,
 				i,
+				w,
 			   *qidx,
 			   *scridx,
 				qoffset,
@@ -503,7 +504,11 @@ ReportSyntaxErrorPosition(const PGresult *result, const char *query)
 	{
 		qidx[i] = qoffset;
 		scridx[i] = scroffset;
-		scroffset += PQdsplen(&query[qoffset], pset.encoding);
+		w = PQdsplen(&query[qoffset], pset.encoding);
+		/* treat control chars as width 1; see tab hack below */
+		if (w <= 0)
+			w = 1;
+		scroffset += w;
 		qoffset += PQmblen(&query[qoffset], pset.encoding);
 	}
 	qidx[i] = qoffset;
@@ -618,7 +623,12 @@ ReportSyntaxErrorPosition(const PGresult *result, const char *query)
 		 */
 		scroffset = 0;
 		for (i = 0; i < msg.len; i += PQmblen(&msg.data[i], pset.encoding))
-			scroffset += PQdsplen(&msg.data[i], pset.encoding);
+		{
+			w = PQdsplen(&msg.data[i], pset.encoding);
+			if (w <= 0)
+				w = 1;
+			scroffset += w;
+		}
 
 		/* Finish and emit the message. */
 		appendPQExpBufferStr(&msg, &wquery[qidx[ibeg]]);