Print combining characters (those reported as having zero width by

PQdsplen()) normally, instead of replacing them by \uXXXX sequences.
Assume that they in fact occupy zero screen space for formatting purposes.
Per gripe from Michael Fuhr and ensuing discussion.

src/bin/psql/mbprint.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2006, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/mbprint.c,v 1.23 2006/10/04 00:30:06 momjian Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/mbprint.c,v 1.24 2006/12/27 19:45:36 tgl Exp $
  */
 
 #include "postgres_fe.h"
@@ -196,7 +196,7 @@ pg_wcssize(unsigned char *pwcs, size_t len, int encoding, int *result_width,
 			break;
 		w = PQdsplen((char *) pwcs, encoding);
 
-		if (chlen == 1)			/* ASCII char */
+		if (chlen == 1)			/* single-byte char */
 		{
 			if (*pwcs == '\n')	/* Newline */
 			{
@@ -211,25 +211,23 @@ pg_wcssize(unsigned char *pwcs, size_t len, int encoding, int *result_width,
 				linewidth += 2;
 				format_size += 2;
 			}
-			else if (w <= 0)	/* Other control char */
+			else if (w < 0)		/* Other control char */
 			{
 				linewidth += 4;
 				format_size += 4;
 			}
-			else
-				/* Output itself */
+			else				/* Output it as-is */
 			{
-				linewidth++;
+				linewidth += w;
 				format_size += 1;
 			}
 		}
-		else if (w <= 0)		/* Non-ascii control char */
+		else if (w < 0)			/* Non-ascii control char */
 		{
 			linewidth += 6;		/* \u0000 */
 			format_size += 6;
 		}
-		else
-			/* All other chars */
+		else					/* All other chars */
 		{
 			linewidth += w;
 			format_size += chlen;
@@ -267,11 +265,11 @@ pg_wcsformat(unsigned char *pwcs, size_t len, int encoding,
 			break;
 		w = PQdsplen((char *) pwcs, encoding);
 
-		if (chlen == 1)			/* single byte char char */
+		if (chlen == 1)			/* single-byte char */
 		{
 			if (*pwcs == '\n')	/* Newline */
 			{
-				*ptr++ = 0;		/* NULL char */
+				*ptr++ = '\0';
 				lines->width = linewidth;
 				linewidth = 0;
 				lines++;
@@ -287,20 +285,19 @@ pg_wcsformat(unsigned char *pwcs, size_t len, int encoding,
 				linewidth += 2;
 				ptr += 2;
 			}
-			else if (w <= 0)	/* Other control char */
+			else if (w < 0)		/* Other control char */
 			{
 				sprintf((char *) ptr, "\\x%02X", *pwcs);
 				linewidth += 4;
 				ptr += 4;
 			}
-			else
-				/* Output itself */
+			else				/* Output it as-is */
 			{
-				linewidth++;
+				linewidth += w;
 				*ptr++ = *pwcs;
 			}
 		}
-		else if (w <= 0)		/* Non-ascii control char */
+		else if (w < 0)			/* Non-ascii control char */
 		{
 			if (encoding == PG_UTF8)
 				sprintf((char *) ptr, "\\u%04X", utf2ucs(pwcs));
@@ -316,8 +313,7 @@ pg_wcsformat(unsigned char *pwcs, size_t len, int encoding,
 			ptr += 6;
 			linewidth += 6;
 		}
-		else
-			/* All other chars */
+		else					/* All other chars */
 		{
 			int			i;
 
@@ -327,13 +323,12 @@ pg_wcsformat(unsigned char *pwcs, size_t len, int encoding,
 		}
 		len -= chlen;
 	}
-	*ptr++ = 0;
+	*ptr++ = '\0';
 	lines->width = linewidth;
 	lines++;
 	count--;
 	if (count > 0)
 		lines->ptr = NULL;
-	return;
 }
 
 unsigned char *