Add explicit tests for division by zero to all user-accessible integer

division and modulo functions, to avoid problems on OS X (which fails to
trap 0 divide at all) and Windows (which traps it in some bizarre
nonstandard fashion).  Standardize on 'division by zero' as the one true
spelling of this error message.  Add regression tests as suggested by
Neil Conway.

src/backend/utils/adt/cash.c

@@ -9,7 +9,7 @@
  * workings can be found in the book "Software Solutions in C" by
  * Dale Schumacher, Academic Press, ISBN: 0-12-632360-7.
  *
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/cash.c,v 1.56 2002/09/04 20:31:27 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/cash.c,v 1.57 2003/03/11 21:01:33 tgl Exp $
  */
 
 #include "postgres.h"
@@ -442,7 +442,7 @@ cash_div_flt8(PG_FUNCTION_ARGS)
 	Cash		result;
 
 	if (f == 0.0)
-		elog(ERROR, "cash_div:  divide by 0.0 error");
+		elog(ERROR, "division by zero");
 
 	result = rint(c / f);
 	PG_RETURN_CASH(result);
@@ -492,7 +492,7 @@ cash_div_flt4(PG_FUNCTION_ARGS)
 	Cash		result;
 
 	if (f == 0.0)
-		elog(ERROR, "cash_div:  divide by 0.0 error");
+		elog(ERROR, "division by zero");
 
 	result = rint(c / f);
 	PG_RETURN_CASH(result);
@@ -543,7 +543,7 @@ cash_div_int4(PG_FUNCTION_ARGS)
 	Cash		result;
 
 	if (i == 0)
-		elog(ERROR, "cash_div_int4: divide by 0 error");
+		elog(ERROR, "division by zero");
 
 	result = rint(c / i);
 
@@ -593,7 +593,7 @@ cash_div_int2(PG_FUNCTION_ARGS)
 	Cash		result;
 
 	if (s == 0)
-		elog(ERROR, "cash_div:  divide by 0 error");
+		elog(ERROR, "division by zero");
 
 	result = rint(c / s);
 	PG_RETURN_CASH(result);

src/backend/utils/adt/char.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/char.c,v 1.33 2002/06/20 20:29:36 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/char.c,v 1.34 2003/03/11 21:01:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -150,6 +150,9 @@ chardiv(PG_FUNCTION_ARGS)
 	char		arg1 = PG_GETARG_CHAR(0);
 	char		arg2 = PG_GETARG_CHAR(1);
 
+	if (arg2 == 0)
+		elog(ERROR, "division by zero");
+
 	PG_RETURN_CHAR((int8) arg1 / (int8) arg2);
 }
 

src/backend/utils/adt/float.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/float.c,v 1.83 2002/11/08 17:37:52 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/float.c,v 1.84 2003/03/11 21:01:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -505,7 +505,7 @@ float4div(PG_FUNCTION_ARGS)
 	double		result;
 
 	if (arg2 == 0.0)
-		elog(ERROR, "float4div: divide by zero error");
+		elog(ERROR, "division by zero");
 
 	/* Do division in float8, then check for overflow */
 	result = (float8) arg1 / (float8) arg2;
@@ -567,7 +567,7 @@ float8div(PG_FUNCTION_ARGS)
 	float8		result;
 
 	if (arg2 == 0.0)
-		elog(ERROR, "float8div: divide by zero error");
+		elog(ERROR, "division by zero");
 
 	result = arg1 / arg2;
 
@@ -1753,7 +1753,7 @@ float48div(PG_FUNCTION_ARGS)
 	float8		result;
 
 	if (arg2 == 0.0)
-		elog(ERROR, "float48div: divide by zero");
+		elog(ERROR, "division by zero");
 
 	result = arg1 / arg2;
 	CheckFloat8Val(result);
@@ -1813,7 +1813,7 @@ float84div(PG_FUNCTION_ARGS)
 	float8		result;
 
 	if (arg2 == 0.0)
-		elog(ERROR, "float84div: divide by zero");
+		elog(ERROR, "division by zero");
 
 	result = arg1 / arg2;
 

src/backend/utils/adt/geo_ops.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_ops.c,v 1.74 2003/01/21 19:44:26 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_ops.c,v 1.75 2003/03/11 21:01:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -3504,7 +3504,7 @@ point_div(PG_FUNCTION_ARGS)
 	div = (p2->x * p2->x) + (p2->y * p2->y);
 
 	if (div == 0.0)
-		elog(ERROR, "point_div:  divide by 0.0 error");
+		elog(ERROR, "division by zero");
 
 	result->x = ((p1->x * p2->x) + (p1->y * p2->y)) / div;
 	result->y = ((p2->x * p1->y) - (p2->y * p1->x)) / div;

src/backend/utils/adt/int.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/int.c,v 1.52 2002/08/22 00:01:43 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/int.c,v 1.53 2003/03/11 21:01:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -551,6 +551,9 @@ int4div(PG_FUNCTION_ARGS)
 	int32		arg1 = PG_GETARG_INT32(0);
 	int32		arg2 = PG_GETARG_INT32(1);
 
+	if (arg2 == 0)
+		elog(ERROR, "division by zero");
+
 	PG_RETURN_INT32(arg1 / arg2);
 }
 
@@ -611,6 +614,9 @@ int2div(PG_FUNCTION_ARGS)
 	int16		arg1 = PG_GETARG_INT16(0);
 	int16		arg2 = PG_GETARG_INT16(1);
 
+	if (arg2 == 0)
+		elog(ERROR, "division by zero");
+
 	PG_RETURN_INT16(arg1 / arg2);
 }
 
@@ -647,6 +653,9 @@ int24div(PG_FUNCTION_ARGS)
 	int16		arg1 = PG_GETARG_INT16(0);
 	int32		arg2 = PG_GETARG_INT32(1);
 
+	if (arg2 == 0)
+		elog(ERROR, "division by zero");
+
 	PG_RETURN_INT32(arg1 / arg2);
 }
 
@@ -683,6 +692,9 @@ int42div(PG_FUNCTION_ARGS)
 	int32		arg1 = PG_GETARG_INT32(0);
 	int16		arg2 = PG_GETARG_INT16(1);
 
+	if (arg2 == 0)
+		elog(ERROR, "division by zero");
+
 	PG_RETURN_INT32(arg1 / arg2);
 }
 
@@ -692,6 +704,9 @@ int4mod(PG_FUNCTION_ARGS)
 	int32		arg1 = PG_GETARG_INT32(0);
 	int32		arg2 = PG_GETARG_INT32(1);
 
+	if (arg2 == 0)
+		elog(ERROR, "division by zero");
+
 	PG_RETURN_INT32(arg1 % arg2);
 }
 
@@ -701,6 +716,9 @@ int2mod(PG_FUNCTION_ARGS)
 	int16		arg1 = PG_GETARG_INT16(0);
 	int16		arg2 = PG_GETARG_INT16(1);
 
+	if (arg2 == 0)
+		elog(ERROR, "division by zero");
+
 	PG_RETURN_INT16(arg1 % arg2);
 }
 
@@ -710,6 +728,9 @@ int24mod(PG_FUNCTION_ARGS)
 	int16		arg1 = PG_GETARG_INT16(0);
 	int32		arg2 = PG_GETARG_INT32(1);
 
+	if (arg2 == 0)
+		elog(ERROR, "division by zero");
+
 	PG_RETURN_INT32(arg1 % arg2);
 }
 
@@ -719,6 +740,9 @@ int42mod(PG_FUNCTION_ARGS)
 	int32		arg1 = PG_GETARG_INT32(0);
 	int16		arg2 = PG_GETARG_INT16(1);
 
+	if (arg2 == 0)
+		elog(ERROR, "division by zero");
+
 	PG_RETURN_INT32(arg1 % arg2);
 }
 

src/backend/utils/adt/int8.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/int8.c,v 1.42 2002/09/18 21:35:22 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/int8.c,v 1.43 2003/03/11 21:01:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -504,6 +504,9 @@ int8div(PG_FUNCTION_ARGS)
 	int64		val1 = PG_GETARG_INT64(0);
 	int64		val2 = PG_GETARG_INT64(1);
 
+	if (val2 == 0)
+		elog(ERROR, "division by zero");
+
 	PG_RETURN_INT64(val1 / val2);
 }
 
@@ -528,6 +531,9 @@ int8mod(PG_FUNCTION_ARGS)
 	int64		val2 = PG_GETARG_INT64(1);
 	int64		result;
 
+	if (val2 == 0)
+		elog(ERROR, "division by zero");
+
 	result = val1 / val2;
 	result *= val2;
 	result = val1 - result;
@@ -621,6 +627,9 @@ int84div(PG_FUNCTION_ARGS)
 	int64		val1 = PG_GETARG_INT64(0);
 	int32		val2 = PG_GETARG_INT32(1);
 
+	if (val2 == 0)
+		elog(ERROR, "division by zero");
+
 	PG_RETURN_INT64(val1 / val2);
 }
 
@@ -657,6 +666,9 @@ int48div(PG_FUNCTION_ARGS)
 	int32		val1 = PG_GETARG_INT32(0);
 	int64		val2 = PG_GETARG_INT64(1);
 
+	if (val2 == 0)
+		elog(ERROR, "division by zero");
+
 	PG_RETURN_INT64(val1 / val2);
 }
 

src/backend/utils/adt/numeric.c

@@ -5,7 +5,7 @@
  *
  *	1998 Jan Wieck
  *
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/numeric.c,v 1.56 2002/10/19 02:08:17 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/numeric.c,v 1.57 2003/03/11 21:01:33 tgl Exp $
  *
  * ----------
  */
@@ -3266,7 +3266,7 @@ div_var(NumericVar *var1, NumericVar *var2, NumericVar *result)
 	 */
 	ndigits_tmp = var2->ndigits + 1;
 	if (ndigits_tmp == 1)
-		elog(ERROR, "division by zero on numeric");
+		elog(ERROR, "division by zero");
 
 	/*
 	 * Determine the result sign, weight and number of digits to calculate

src/backend/utils/adt/timestamp.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/timestamp.c,v 1.79 2003/02/27 21:36:58 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/timestamp.c,v 1.80 2003/03/11 21:01:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1869,7 +1869,7 @@ interval_div(PG_FUNCTION_ARGS)
 	result = (Interval *) palloc(sizeof(Interval));
 
 	if (factor == 0.0)
-		elog(ERROR, "interval_div: divide by 0.0 error");
+		elog(ERROR, "division by zero");
 
 #ifdef HAVE_INT64_TIMESTAMP
 	result->month = (span->month / factor);

src/test/regress/expected/errors.out

@@ -18,7 +18,7 @@ select 1;
 -- notify pg_class
 --
 --
--- RETRIEVE
+-- SELECT
  
 -- missing relation name 
 select;
@@ -54,7 +54,7 @@ ERROR:  parser: parse error at or near ";" at character 12
 delete from nonesuch;
 ERROR:  Relation "nonesuch" does not exist
 --
--- DESTROY
+-- DROP
  
 -- missing relation name (this had better not wildcard!) 
 drop table;
@@ -63,7 +63,7 @@ ERROR:  parser: parse error at or near ";" at character 11
 drop table nonesuch;
 ERROR:  table "nonesuch" does not exist
 --
--- RENAME
+-- ALTER TABLE
  
 -- relation renaming 
 -- missing relation name 
@@ -104,7 +104,7 @@ WARNING:  ROLLBACK: no transaction in progress
 end;
 WARNING:  COMMIT: no transaction in progress
 --
--- DEFINE AGGREGATE
+-- CREATE AGGREGATE
 -- sfunc/finalfunc type disagreement 
 create aggregate newavg2 (sfunc = int4pl,
 			  basetype = int4,
@@ -118,7 +118,7 @@ create aggregate newcnt1 (sfunc = int4inc,
 			  initcond = '0');
 ERROR:  Define: "basetype" unspecified
 --
--- REMOVE INDEX
+-- DROP INDEX
  
 -- missing index name 
 drop index;
@@ -130,7 +130,7 @@ ERROR:  parser: parse error at or near "314159" at character 12
 drop index nonesuch;
 ERROR:  index "nonesuch" does not exist
 --
--- REMOVE AGGREGATE
+-- DROP AGGREGATE
  
 -- missing aggregate name 
 drop aggregate;
@@ -151,7 +151,7 @@ ERROR:  RemoveAggregate: aggregate nonesuch(integer) does not exist
 drop aggregate newcnt (float4);
 ERROR:  RemoveAggregate: aggregate newcnt(real) does not exist
 --
--- REMOVE FUNCTION
+-- DROP FUNCTION
  
 -- missing function name 
 drop function ();
@@ -163,7 +163,7 @@ ERROR:  parser: parse error at or near "314159" at character 15
 drop function nonesuch();
 ERROR:  RemoveFunction: function nonesuch() does not exist
 --
--- REMOVE TYPE
+-- DROP TYPE
  
 -- missing type name 
 drop type;
@@ -237,3 +237,28 @@ ERROR:  parser: parse error at or near "instance" at character 6
 -- no such rule 
 drop rewrite rule nonesuch;
 ERROR:  parser: parse error at or near "rewrite" at character 6
+--
+-- Check that division-by-zero is properly caught.
+--
+select 1/0;
+ERROR:  division by zero
+select 1::int8/0;
+ERROR:  division by zero
+select 1/0::int8;
+ERROR:  division by zero
+select 1::int2/0;
+ERROR:  division by zero
+select 1/0::int2;
+ERROR:  division by zero
+select 1::numeric/0;
+ERROR:  division by zero
+select 1/0::numeric;
+ERROR:  division by zero
+select 1::float8/0;
+ERROR:  division by zero
+select 1/0::float8;
+ERROR:  division by zero
+select 1::float4/0;
+ERROR:  division by zero
+select 1/0::float4;
+ERROR:  division by zero

src/test/regress/expected/float4-exp-three-digits.out

@@ -113,7 +113,7 @@ SELECT '' AS three, f.f1, f.f1 - '-10' AS x FROM FLOAT4_TBL f
 
 -- test divide by zero
 SELECT '' AS bad, f.f1 / '0.0' from FLOAT4_TBL f;
-ERROR:  float4div: divide by zero error
+ERROR:  division by zero
 SELECT '' AS five, FLOAT4_TBL.*;
  five |      f1      
 ------+--------------

src/test/regress/expected/float4.out

@@ -113,7 +113,7 @@ SELECT '' AS three, f.f1, f.f1 - '-10' AS x FROM FLOAT4_TBL f
 
 -- test divide by zero
 SELECT '' AS bad, f.f1 / '0.0' from FLOAT4_TBL f;
-ERROR:  float4div: divide by zero error
+ERROR:  division by zero
 SELECT '' AS five, FLOAT4_TBL.*;
  five |     f1      
 ------+-------------

src/test/regress/expected/float8-exp-three-digits.out

@@ -257,7 +257,7 @@ ERROR:  can't take log of a negative number
 SELECT '' AS bad, exp(f.f1) from FLOAT8_TBL f;
 ERROR:  exp() result is out of range
 SELECT '' AS bad, f.f1 / '0.0' from FLOAT8_TBL f;
-ERROR:  float8div: divide by zero error
+ERROR:  division by zero
 SELECT '' AS five, FLOAT8_TBL.*;
  five |          f1           
 ------+-----------------------

src/test/regress/expected/float8-fp-exception.out

@@ -257,7 +257,7 @@ ERROR:  can't take log of a negative number
 SELECT '' AS bad, exp(f.f1) from FLOAT8_TBL f;
 ERROR:  exp() result is out of range
 SELECT '' AS bad, f.f1 / '0.0' from FLOAT8_TBL f;
-ERROR:  float8div: divide by zero error
+ERROR:  division by zero
 SELECT '' AS five, FLOAT8_TBL.*;
  five |          f1           
 ------+-----------------------

src/test/regress/expected/float8-small-is-zero.out

@@ -257,7 +257,7 @@ ERROR:  can't take log of a negative number
 SELECT '' AS bad, exp(f.f1) from FLOAT8_TBL f;
 ERROR:  exp() result is out of range
 SELECT '' AS bad, f.f1 / '0.0' from FLOAT8_TBL f;
-ERROR:  float8div: divide by zero error
+ERROR:  division by zero
 SELECT '' AS five, FLOAT8_TBL.*;
  five |          f1           
 ------+-----------------------

src/test/regress/expected/float8.out

@@ -257,7 +257,7 @@ ERROR:  can't take log of a negative number
 SELECT '' AS bad, exp(f.f1) from FLOAT8_TBL f;
 ERROR:  exp() result is out of range
 SELECT '' AS bad, f.f1 / '0.0' from FLOAT8_TBL f;
-ERROR:  float8div: divide by zero error
+ERROR:  division by zero
 SELECT '' AS five, FLOAT8_TBL.*;
  five |          f1           
 ------+-----------------------

src/test/regress/sql/errors.sql

@@ -17,7 +17,7 @@ select 1;
 --
 
 --
--- RETRIEVE
+-- SELECT
  
 -- missing relation name 
 select;
@@ -55,7 +55,7 @@ delete from nonesuch;
 
 
 --
--- DESTROY
+-- DROP
  
 -- missing relation name (this had better not wildcard!) 
 drop table;
@@ -65,8 +65,7 @@ drop table nonesuch;
 
 
 --
--- RENAME
+-- ALTER TABLE
- 
  
 -- relation renaming 
 
@@ -112,7 +111,7 @@ end;
 
 
 --
--- DEFINE AGGREGATE
+-- CREATE AGGREGATE
 
 -- sfunc/finalfunc type disagreement 
 create aggregate newavg2 (sfunc = int4pl,
@@ -128,7 +127,7 @@ create aggregate newcnt1 (sfunc = int4inc,
 
 
 --
--- REMOVE INDEX
+-- DROP INDEX
  
 -- missing index name 
 drop index;
@@ -141,7 +140,7 @@ drop index nonesuch;
 
 
 --
--- REMOVE AGGREGATE
+-- DROP AGGREGATE
  
 -- missing aggregate name 
 drop aggregate;
@@ -163,7 +162,7 @@ drop aggregate newcnt (float4);
 
 
 --
--- REMOVE FUNCTION
+-- DROP FUNCTION
  
 -- missing function name 
 drop function ();
@@ -176,7 +175,7 @@ drop function nonesuch();
 
 
 --
--- REMOVE TYPE
+-- DROP TYPE
  
 -- missing type name 
 drop type;
@@ -252,3 +251,28 @@ drop instance rule nonesuch on noplace;
 -- no such rule 
 drop rewrite rule nonesuch;
 
+--
+-- Check that division-by-zero is properly caught.
+--
+
+select 1/0;
+
+select 1::int8/0;
+
+select 1/0::int8;
+
+select 1::int2/0;
+
+select 1/0::int2;
+
+select 1::numeric/0;
+
+select 1/0::numeric;
+
+select 1::float8/0;
+
+select 1/0::float8;
+
+select 1::float4/0;
+
+select 1/0::float4;