Handling CASE expression when one branch is of decimal/numeric and other branch is of smallmoney/money. (babelfish-for-postgresql#3719)

Currently, we treat typmod for smallmoney/money datatype as default which leads to output differences in many cases.

Following are the fixes introduced in this PR :

Introduce typmod handling for smallmoney/money datatype for objects like table/procedure/views/functions/casts and handling their upgrade scenarios.
We are also handling p&s for declared variables, nested case expressions and unions having smallmoney/money as one of it's node.
It also takes case of round vs truncation behaviour around edge cases for fixeddecimal multiplication
Money/smallmoney and Numeric Arithmetic operations - precision and sclae correction and fixing TDS protocol Errors.
T_Param node handling for fixeddecimal dataypes (money and smallmoney) when numeric is another operand.
T_Aggref handling for Sum/Avg for fixeddecimal and other fixed length datatypes when numeric is another operand.
Handing typmod for smallmoney/money in pg catalogs for views metadata and during dump-restore.
Handling money/smallmoney typmod and fixeddecimal typmodin during dump-restore and by-passing typmod while deparsing for ISC check constraint.
Avoiding crashes and wrong results by updating sanity checks and setting intermittent result size appropirately for bigint and fixeddecimal multiplication.
Signed-off-by: Tanya Gupta [email protected]

Engine PR : babelfish-for-postgresql/postgresql_modified_for_babelfish#575

Author: tanyagupta17

contrib/babelfishpg_tsql/src/pltsql_coerce.c

@@ -1228,6 +1228,7 @@ resolve_numeric_typmod_from_exp(Plan *plan, Node *expr, bool *found)
 		case T_Param:
 			{
 				Param *param = (Param *) expr;
+
 				if (param->paramtypmod == -1)
 				{
 					/* UDT handling in T_Param */
@@ -1247,11 +1248,11 @@ resolve_numeric_typmod_from_exp(Plan *plan, Node *expr, bool *found)
 						return ((BIGINT_PRECISION_RADIX << 16) | 0) + VARHDRSZ;
 					else if (param->paramtype == INT2OID)
 						return ((SMALLINT_PRECISION_RADIX << 16) | 0) + VARHDRSZ;
-					else if (plan && (*common_utility_plugin_ptr->is_tsql_tinyint_datatype) (param->paramtype))
-						return ((TINYINT_PRECISION_RADIX << 16) | 0) + VARHDRSZ;
 				}
 
-				if (!is_numeric_datatype(param->paramtype))
+				if (!is_numeric_datatype(param->paramtype) &&
+					!(*common_utility_plugin_ptr->is_tsql_money_datatype)(param->paramtype) &&
+					!(*common_utility_plugin_ptr->is_tsql_smallmoney_datatype)(param->paramtype))
 				{
 					/* typmod is undefined */
 					if (found != NULL) *found = false;
@@ -1831,7 +1832,8 @@ resolve_numeric_typmod_from_exp(Plan *plan, Node *expr, bool *found)
 					 * tinyint, smallint, int will have aggtype type as int
 					 * bigint will have aggtype type as bigint.
 					 */
-					if ((*common_utility_plugin_ptr->is_tsql_money_datatype)(aggref->aggtype))
+					if ((*common_utility_plugin_ptr->is_tsql_money_datatype)(aggref->aggtype) ||
+						(*common_utility_plugin_ptr->is_tsql_smallmoney_datatype)(aggref->aggtype))
 					{
 						return TSQL_MONEY_TYPMOD;
 					}