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.

1 files changed, 25 insertions, 1 deletions

diff --git a/src/backend/utils/adt/int.c b/src/backend/utils/adt/int.c
index 859e78b58c..73687d55ec 100644
--- a/src/backend/utils/adt/int.c
+++ b/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);
 }