Check explicitly for valid input strings for both TRUE and FALSE.

Allow true/false, yes/no, 1/0. Throw elog warning if anything else.
Allow shorter strings, so "t", "tr", "tru" and "true" match "true".
Old behavior accepted anything starting with "t" as TRUE,
 everything else as FALSE.

src/backend/utils/adt/bool.c

@@ -7,11 +7,12 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/bool.c,v 1.8 1997/10/17 05:38:32 thomas Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/bool.c,v 1.9 1997/10/25 05:09:58 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
 
+#include <string.h>
 #include "postgres.h"
 
 #include "utils/builtins.h"		/* where the declarations go */
@@ -26,10 +27,6 @@
  *
  * Check explicitly for "true/false" and TRUE/FALSE, 1/0, YES/NO.
  * Reject other values. - thomas 1997-10-05
- * For now, allow old behavior of everything FALSE if not TRUE.
- * After v6.2.1 release, then enable code to reject goofy values.
- * Also, start checking the entire string rather than just the first character.
- * - thomas 1997-10-16
  *
  * In the switch statement, check the most-used possibilities first.
  */
@@ -39,33 +36,43 @@ boolin(char *b)
 	switch(*b) {
 		case 't':
 		case 'T':
-			return (TRUE);
+			if (strncasecmp(b, "true", strlen(b)) == 0)
+				return (TRUE);
 			break;
 
 		case 'f':
 		case 'F':
-			return (FALSE);
+			if (strncasecmp(b, "false", strlen(b)) == 0)
+				return (FALSE);
 			break;
 
 		case 'y':
 		case 'Y':
+			if (strncasecmp(b, "yes", strlen(b)) == 0)
+				return (TRUE);
+			break;
+
 		case '1':
-			return (TRUE);
+			if (strncasecmp(b, "1", strlen(b)) == 0)
+				return (TRUE);
 			break;
 
 		case 'n':
 		case 'N':
+			if (strncasecmp(b, "no", strlen(b)) == 0)
+				return (FALSE);
+			break;
+
 		case '0':
-			return (FALSE);
+			if (strncasecmp(b, "0", strlen(b)) == 0)
+				return (FALSE);
 			break;
 
 		default:
-#if FALSE
-			elog(WARN,"Invalid input string '%s'\n", b);
-#endif
 			break;
 	}
 
+	elog(WARN,"Invalid input string '%s'\n", b);
 	return (FALSE);
 } /* boolin() */