New improved version of bpcharin() may have got the truncation case

right, but it failed to get the padding case right.

This was obscured by subsequent application of bpchar() in all but one
regression test case, and that one didn't fail in an obvious way ---
trailing blanks are hard to see.  Add another test case to make it
more obvious if it breaks again.

src/backend/utils/adt/varchar.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/varchar.c,v 1.78 2001/05/21 16:54:46 petere Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/varchar.c,v 1.79 2001/06/01 17:49:16 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -65,10 +65,8 @@ Datum
 bpcharin(PG_FUNCTION_ARGS)
 {
 	char	   *s = PG_GETARG_CSTRING(0);
-
 #ifdef NOT_USED
 	Oid			typelem = PG_GETARG_OID(1);
-
 #endif
 	int32		atttypmod = PG_GETARG_INT32(2);
 	BpChar	   *result;
@@ -77,45 +75,46 @@ bpcharin(PG_FUNCTION_ARGS)
 	int			i;
 
 	len = strlen(s);
-	maxlen = atttypmod - VARHDRSZ;
 
-	if (atttypmod >= (int32) VARHDRSZ && len > maxlen)
+	/* If typmod is -1 (or invalid), use the actual string length */
+	if (atttypmod < (int32) VARHDRSZ)
+		maxlen = len;
+	else
+		maxlen = atttypmod - VARHDRSZ;
+
+	if (len > maxlen)
 	{
+		/* Verify that extra characters are spaces, and clip them off */
 #ifdef MULTIBYTE
 		size_t mbmaxlen = pg_mbcliplen(s, len, maxlen);
 
 		if (strspn(s + mbmaxlen, " ") == len - mbmaxlen)
 			len = mbmaxlen;
+		else
+			elog(ERROR, "value too long for type character(%d)", maxlen);
+		Assert(len <= maxlen);
 #else
 		if (strspn(s + maxlen, " ") == len - maxlen)
-			/* clip extra spaces */
 			len = maxlen;
-#endif
 		else
 			elog(ERROR, "value too long for type character(%d)", maxlen);
+#endif
 	}
-	else
-		/* If typmod is -1 (or invalid), use the actual string length */
-		maxlen = len;
 
 	result = palloc(maxlen + VARHDRSZ);
 	VARATT_SIZEP(result) = maxlen + VARHDRSZ;
 	r = VARDATA(result);
-	for (i = 0; i < len; i++, r++, s++)
-	{
-		*r = *s;
-		if (*r == '\0')
-			break;
-	}
-
-#ifdef CYR_RECODE
-	convertstr(VARDATA(result), len, 0);
-#endif
+	for (i = 0; i < len; i++)
+		*r++ = *s++;
 
 	/* blank pad the string if necessary */
 	for (; i < maxlen; i++)
 		*r++ = ' ';
 
+#ifdef CYR_RECODE
+	convertstr(VARDATA(result), len, 0);
+#endif
+
 	PG_RETURN_BPCHAR_P(result);
 }
 
@@ -162,11 +161,12 @@ bpchar(PG_FUNCTION_ARGS)
 
 	len = VARSIZE(source);
 	/* No work if typmod is invalid or supplied data matches it already */
-	if (len < (int32) VARHDRSZ || len == maxlen)
+	if (maxlen < (int32) VARHDRSZ || len == maxlen)
 		PG_RETURN_BPCHAR_P(source);
 
 	if (len > maxlen)
 	{
+		/* Verify that extra characters are spaces, and clip them off */
 #ifdef MULTIBYTE
 		size_t		maxmblen;
 
@@ -179,13 +179,13 @@ bpchar(PG_FUNCTION_ARGS)
 					 maxlen - VARHDRSZ);
 
 		len = maxmblen;
+		Assert(len <= maxlen);
 #else
 		for (i = maxlen - VARHDRSZ; i < len - VARHDRSZ; i++)
 			if (*(VARDATA(source) + i) != ' ')
 				elog(ERROR, "value too long for type character(%d)",
 					 maxlen - VARHDRSZ);
 
-		/* clip extra spaces */
 		len = maxlen;
 #endif
 	}
@@ -196,7 +196,7 @@ bpchar(PG_FUNCTION_ARGS)
 	VARATT_SIZEP(result) = maxlen;
 	r = VARDATA(result);
 
-	for (i = 0; (i < maxlen - VARHDRSZ) && (i < len - VARHDRSZ); i++)
+	for (i = 0; i < len - VARHDRSZ; i++)
 		*r++ = *s++;
 
 	/* blank pad the string if necessary */
@@ -340,10 +340,8 @@ Datum
 varcharin(PG_FUNCTION_ARGS)
 {
 	char	   *s = PG_GETARG_CSTRING(0);
-
 #ifdef NOT_USED
 	Oid			typelem = PG_GETARG_OID(1);
-
 #endif
 	int32		atttypmod = PG_GETARG_INT32(2);
 	VarChar    *result;
@@ -354,6 +352,7 @@ varcharin(PG_FUNCTION_ARGS)
 
 	if (atttypmod >= (int32) VARHDRSZ && len > maxlen)
 	{
+		/* Verify that extra characters are spaces, and clip them off */
 #ifdef MULTIBYTE
 		size_t mbmaxlen = pg_mbcliplen(s, len, maxlen);
 
@@ -361,7 +360,6 @@ varcharin(PG_FUNCTION_ARGS)
 			len = mbmaxlen;
 #else
 		if (strspn(s + maxlen, " ") == len - maxlen)
-			/* clip extra spaces */
 			len = maxlen;
 #endif
 		else
@@ -419,6 +417,7 @@ varchar(PG_FUNCTION_ARGS)
 	int			i;
 
 	len = VARSIZE(source);
+	/* No work if typmod is invalid or supplied data fits it already */
 	if (maxlen < (int32) VARHDRSZ || len <= maxlen)
 		PG_RETURN_VARCHAR_P(source);
 

src/test/regress/expected/strings.out

@@ -481,10 +481,16 @@ SELECT text 'text' || ' and unknown' AS "Concat text to unknown type";
  text and unknown
 (1 row)
 
+SELECT char(20) 'characters' || 'and text' AS "Concat char to unknown type";
+ Concat char to unknown type  
+------------------------------
+ characters          and text
+(1 row)
+
 SELECT text 'text' || char(20) ' and characters' AS "Concat text to char";
- Concat text to char 
----------------------
- text and characters
+   Concat text to char    
+--------------------------
+ text and characters     
 (1 row)
 
 SELECT text 'text' || varchar ' and varchar' AS "Concat text to varchar";

src/test/regress/sql/strings.sql

@@ -160,6 +160,8 @@ SELECT 'unknown' || ' and unknown' AS "Concat unknown types";
 
 SELECT text 'text' || ' and unknown' AS "Concat text to unknown type";
 
+SELECT char(20) 'characters' || 'and text' AS "Concat char to unknown type";
+
 SELECT text 'text' || char(20) ' and characters' AS "Concat text to char";
 
 SELECT text 'text' || varchar ' and varchar' AS "Concat text to varchar";