Emit a warning when an empty string is input to the oid, float4, and

float8 types. This begins the deprecation of this feature: in 7.6,
this input will be rejected.

Also added a new error code for warnings about deprecated features,
and updated the regression tests.

doc/src/sgml/errcodes.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/errcodes.sgml,v 1.2 2003/11/29 19:51:37 pgsql Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/errcodes.sgml,v 1.3 2004/03/04 21:47:18 neilc Exp $ -->
 
 <appendix id="errcodes-appendix">
  <title><productname>PostgreSQL</productname> Error Codes</title>
@@ -95,6 +95,10 @@
 <entry>WARNING STRING DATA RIGHT TRUNCATION</entry>
 </row>
 
+<row>
+<entry><literal>01P01</literal></entry>
+<entry>WARNING DEPRECATED FEATURE</entry>
+</row>
 
 <row>
 <entry>Class 02</entry>

src/backend/utils/adt/float.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/float.c,v 1.96 2003/11/29 19:51:58 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/float.c,v 1.97 2004/03/04 21:47:18 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -208,6 +208,19 @@ float4in(PG_FUNCTION_ARGS)
 					 errmsg("\"%s\" is out of range for type real", num)));
 	}
 
+	/*
+	 * In releases prior to 7.5, we accepted an empty string as valid
+	 * input (yielding a float4 of 0). In 7.5, we accept empty
+	 * strings, but emit a warning noting that the feature is
+	 * deprecated. In 7.6+, the warning should be replaced by an error.
+	 */
+	if (num == endptr)
+		ereport(WARNING,
+				(errcode(ERRCODE_WARNING_DEPRECATED_FEATURE),
+				 errmsg("deprecated input syntax for type real: \"\""),
+				 errdetail("This input will be rejected in "
+						   "a future release of PostgreSQL.")));
+
 	/*
 	 * if we get here, we have a legal double, still need to check to see
 	 * if it's a legal float
@@ -309,6 +322,19 @@ float8in(PG_FUNCTION_ARGS)
 					 errmsg("\"%s\" is out of range for type double precision", num)));
 	}
 
+	/*
+	 * In releases prior to 7.5, we accepted an empty string as valid
+	 * input (yielding a float8 of 0). In 7.5, we accept empty
+	 * strings, but emit a warning noting that the feature is
+	 * deprecated. In 7.6+, the warning should be replaced by an error.
+	 */
+	if (num == endptr)
+		ereport(WARNING,
+				(errcode(ERRCODE_WARNING_DEPRECATED_FEATURE),
+				 errmsg("deprecated input syntax for type double precision: \"\""),
+				 errdetail("This input will be rejected in "
+						   "a future release of PostgreSQL.")));
+
 	CheckFloat8Val(val);
 
 	PG_RETURN_FLOAT8(val);

src/backend/utils/adt/oid.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/oid.c,v 1.54 2004/02/18 00:01:34 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/oid.c,v 1.55 2004/03/04 21:47:18 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -40,15 +40,27 @@ oidin_subr(const char *funcname, const char *s, char **endloc)
 	 * strtoul() normally only sets ERANGE.  On some systems it also may
 	 * set EINVAL, which simply means it couldn't parse the input string.
 	 * This is handled by the second "if" consistent across platforms.
-	 * Note that for historical reasons we accept an empty string as
-	 * meaning 0.
 	 */
 	if (errno && errno != ERANGE && errno != EINVAL)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 				 errmsg("invalid input syntax for type oid: \"%s\"",
 						s)));
-	if (endptr == s && *endptr)
+
+	/*
+	 * In releases prior to 7.5, we accepted an empty string as valid
+	 * input (yielding an OID of 0). In 7.5, we accept empty strings,
+	 * but emit a warning noting that the feature is deprecated. In
+	 * 7.6+, the warning should be replaced by an error.
+	 */
+	if (*s == '\0')
+		ereport(WARNING,
+				(errcode(ERRCODE_WARNING_DEPRECATED_FEATURE),
+				 errmsg("deprecated input syntax for type oid: \"\""),
+				 errdetail("This input will be rejected in "
+						   "a future release of PostgreSQL.")));
+
+	if (endptr == s && *s)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 				 errmsg("invalid input syntax for type oid: \"%s\"",

src/include/utils/errcodes.h

@@ -11,7 +11,7 @@
  *
  * Copyright (c) 2003, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/include/utils/errcodes.h,v 1.7 2003/11/29 22:41:15 pgsql Exp $
+ * $PostgreSQL: pgsql/src/include/utils/errcodes.h,v 1.8 2004/03/04 21:47:18 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -44,6 +44,7 @@
 #define ERRCODE_WARNING_IMPLICIT_ZERO_BIT_PADDING	MAKE_SQLSTATE('0','1', '0','0','8')
 #define ERRCODE_WARNING_NULL_VALUE_ELIMINATED_IN_SET_FUNCTION	MAKE_SQLSTATE('0','1', '0','0','3')
 #define ERRCODE_WARNING_STRING_DATA_RIGHT_TRUNCATION	MAKE_SQLSTATE('0','1', '0','0','4')
+#define ERRCODE_WARNING_DEPRECATED_FEATURE	MAKE_SQLSTATE('0','1', 'P','0','1')
 
 /* Class 02 - No Data --- this is also a warning class per SQL99 */
 /* (do not use this class for failure conditions!) */

src/test/regress/expected/oid.out

@@ -7,7 +7,6 @@ INSERT INTO OID_TBL(f1) VALUES ('1235');
 INSERT INTO OID_TBL(f1) VALUES ('987');
 INSERT INTO OID_TBL(f1) VALUES ('-1040');
 INSERT INTO OID_TBL(f1) VALUES ('99999999');
-INSERT INTO OID_TBL(f1) VALUES ('');
 -- bad inputs 
 INSERT INTO OID_TBL(f1) VALUES ('asdfasd');
 ERROR:  invalid input syntax for type oid: "asdfasd"
@@ -21,8 +20,7 @@ SELECT '' AS six, OID_TBL.*;
      |        987
      | 4294966256
      |   99999999
-     |          0
-(6 rows)
+(5 rows)
 
 SELECT '' AS one, o.* FROM OID_TBL o WHERE o.f1 = 1234;
  one |  f1  
@@ -37,23 +35,20 @@ SELECT '' AS five, o.* FROM OID_TBL o WHERE o.f1 <> '1234';
       |        987
       | 4294966256
       |   99999999
-      |          0
-(5 rows)
+(4 rows)
 
 SELECT '' AS three, o.* FROM OID_TBL o WHERE o.f1 <= '1234';
  three |  f1  
 -------+------
        | 1234
        |  987
-       |    0
-(3 rows)
+(2 rows)
 
 SELECT '' AS two, o.* FROM OID_TBL o WHERE o.f1 < '1234';
  two | f1  
 -----+-----
      | 987
-     |   0
-(2 rows)
+(1 row)
 
 SELECT '' AS four, o.* FROM OID_TBL o WHERE o.f1 >= '1234';
  four |     f1     

src/test/regress/sql/oid.sql

@@ -14,8 +14,6 @@ INSERT INTO OID_TBL(f1) VALUES ('-1040');
 
 INSERT INTO OID_TBL(f1) VALUES ('99999999');
 
-INSERT INTO OID_TBL(f1) VALUES ('');
-
 -- bad inputs 
 
 INSERT INTO OID_TBL(f1) VALUES ('asdfasd');