Dept of second thoughts: don't use the new wide-character upper/lower

code if we are running in a single-byte encoding.  No point in the
extra overhead in that case.

src/backend/utils/adt/oracle_compat.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	$PostgreSQL: pgsql/src/backend/utils/adt/oracle_compat.c,v 1.52 2004/05/26 16:16:03 tgl Exp $
+ *	$PostgreSQL: pgsql/src/backend/utils/adt/oracle_compat.c,v 1.53 2004/06/06 22:17:01 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -166,6 +166,9 @@ Datum
 lower(PG_FUNCTION_ARGS)
 {
 #ifdef USE_WIDE_UPPER_LOWER
+	/* use wide char code only when max encoding length > one */
+	if (pg_database_encoding_max_length() > 1)
+	{
 		text	   *string = PG_GETARG_TEXT_P(0);
 		text	   *result;
 		wchar_t	   *workspace;
@@ -181,9 +184,10 @@ lower(PG_FUNCTION_ARGS)
 		pfree(workspace);
 
 		PG_RETURN_TEXT_P(result);
-
-#else /* !USE_WIDE_UPPER_LOWER */
-
+	}
+	else
+#endif /* USE_WIDE_UPPER_LOWER */
+	{
 		text	   *string = PG_GETARG_TEXT_P_COPY(0);
 		char	   *ptr;
 		int			m;
@@ -199,7 +203,7 @@ lower(PG_FUNCTION_ARGS)
 		}
 
 		PG_RETURN_TEXT_P(string);
-#endif /* USE_WIDE_UPPER_LOWER */
+	}
 }
 
 
@@ -221,6 +225,9 @@ Datum
 upper(PG_FUNCTION_ARGS)
 {
 #ifdef USE_WIDE_UPPER_LOWER
+	/* use wide char code only when max encoding length > one */
+	if (pg_database_encoding_max_length() > 1)
+	{
 		text	   *string = PG_GETARG_TEXT_P(0);
 		text	   *result;
 		wchar_t	   *workspace;
@@ -236,9 +243,10 @@ upper(PG_FUNCTION_ARGS)
 		pfree(workspace);
 
 		PG_RETURN_TEXT_P(result);
-
-#else /* !USE_WIDE_UPPER_LOWER */
-
+	}
+	else
+#endif /* USE_WIDE_UPPER_LOWER */
+	{
 		text	   *string = PG_GETARG_TEXT_P_COPY(0);
 		char	   *ptr;
 		int			m;
@@ -254,7 +262,7 @@ upper(PG_FUNCTION_ARGS)
 		}
 
 		PG_RETURN_TEXT_P(string);
-#endif /* USE_WIDE_UPPER_LOWER */
+	}
 }
 
 
@@ -279,6 +287,9 @@ Datum
 initcap(PG_FUNCTION_ARGS)
 {
 #ifdef USE_WIDE_UPPER_LOWER
+	/* use wide char code only when max encoding length > one */
+	if (pg_database_encoding_max_length() > 1)
+	{
 		text	   *string = PG_GETARG_TEXT_P(0);
 		text	   *result;
 		wchar_t	   *workspace;
@@ -301,10 +312,12 @@ initcap(PG_FUNCTION_ARGS)
 		pfree(workspace);
 
 		PG_RETURN_TEXT_P(result);
-
-#else /* !USE_WIDE_UPPER_LOWER */
-
+	}
+	else
+#endif /* USE_WIDE_UPPER_LOWER */
+	{
 		text	   *string = PG_GETARG_TEXT_P_COPY(0);
+		int			wasalnum = 0;
 		char	   *ptr;
 		int			m;
 
@@ -312,25 +325,18 @@ initcap(PG_FUNCTION_ARGS)
 		ptr = VARDATA(string);
 		m = VARSIZE(string) - VARHDRSZ;
 
-	if (m > 0)
-	{
-		*ptr = toupper((unsigned char) *ptr);
-		ptr++;
-		m--;
-	}
-
 		while (m-- > 0)
 		{
-		/* Oracle capitalizes after all non-alphanumeric */
-		if (!isalnum((unsigned char) ptr[-1]))
-			*ptr = toupper((unsigned char) *ptr);
-		else
+			if (wasalnum)
 				*ptr = tolower((unsigned char) *ptr);
+			else
+				*ptr = toupper((unsigned char) *ptr);
+			wasalnum = isalnum((unsigned char) *ptr);
 			ptr++;
 		}
 
 		PG_RETURN_TEXT_P(string);
-#endif /* USE_WIDE_UPPER_LOWER */
+	}
 }