Modify the handling of RAISE without parameters so that the error it throws

can be caught in the same places that could catch an ordinary RAISE ERROR
in the same location.  The previous coding insisted on throwing the error
from the block containing the active exception handler; which is arguably
more surprising, and definitely unlike Oracle's behavior.

Not back-patching, since this is a pretty obscure corner case.  The risk
of breaking somebody's code in a minor version update seems to outweigh
any possible benefit.

Piyush Newe, reviewed by David Fetter

2 files changed, 30 insertions, 22 deletions

diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index e1f48e3d75d..a1ff9120f47 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.261 2010/07/06 19:19:01 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.262 2010/08/09 02:25:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -327,10 +327,6 @@ plpgsql_exec_function(PLpgSQL_function *func, FunctionCallInfo fcinfo)
 			ereport(ERROR,
 					(errcode(ERRCODE_SYNTAX_ERROR),
 					 errmsg("CONTINUE cannot be used outside a loop")));
-		else if (rc == PLPGSQL_RC_RERAISE)
-			ereport(ERROR,
-					(errcode(ERRCODE_SYNTAX_ERROR),
-					 errmsg("RAISE without parameters cannot be used outside an exception handler")));
 		else
 			ereport(ERROR,
 			   (errcode(ERRCODE_S_R_E_FUNCTION_EXECUTED_NO_RETURN_STATEMENT),
@@ -695,10 +691,6 @@ plpgsql_exec_trigger(PLpgSQL_function *func,
 			ereport(ERROR,
 					(errcode(ERRCODE_SYNTAX_ERROR),
 					 errmsg("CONTINUE cannot be used outside a loop")));
-		else if (rc == PLPGSQL_RC_RERAISE)
-			ereport(ERROR,
-					(errcode(ERRCODE_SYNTAX_ERROR),
-					 errmsg("RAISE without parameters cannot be used outside an exception handler")));
 		else
 			ereport(ERROR,
 			   (errcode(ERRCODE_S_R_E_FUNCTION_EXECUTED_NO_RETURN_STATEMENT),
@@ -1019,6 +1011,7 @@ exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
 		MemoryContext oldcontext = CurrentMemoryContext;
 		ResourceOwner oldowner = CurrentResourceOwner;
 		ExprContext *old_eval_econtext = estate->eval_econtext;
+		ErrorData *save_cur_error = estate->cur_error;
 
 		estate->err_text = gettext_noop("during statement block entry");
 
@@ -1130,6 +1123,12 @@ exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
 									unpack_sql_state(edata->sqlerrcode));
 					assign_text_var(errm_var, edata->message);
 
+					/*
+					 * Also set up cur_error so the error data is accessible
+					 * inside the handler.
+					 */
+					estate->cur_error = edata;
+
 					estate->err_text = NULL;
 
 					rc = exec_stmts(estate, exception->action);
@@ -1141,14 +1140,17 @@ exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
 					errm_var->value = (Datum) 0;
 					errm_var->isnull = true;
 
-					/* re-throw error if requested by handler */
-					if (rc == PLPGSQL_RC_RERAISE)
-						ReThrowError(edata);
-
 					break;
 				}
 			}
 
+			/*
+			 * Restore previous state of cur_error, whether or not we executed
+			 * a handler.  This is needed in case an error got thrown from
+			 * some inner block's exception handler.
+			 */
+			estate->cur_error = save_cur_error;
+
 			/* If no match found, re-throw the error */
 			if (e == NULL)
 				ReThrowError(edata);
@@ -1156,6 +1158,8 @@ exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
 				FreeErrorData(edata);
 		}
 		PG_END_TRY();
+
+		Assert(save_cur_error == estate->cur_error);
 	}
 	else
 	{
@@ -1177,7 +1181,6 @@ exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
 		case PLPGSQL_RC_OK:
 		case PLPGSQL_RC_RETURN:
 		case PLPGSQL_RC_CONTINUE:
-		case PLPGSQL_RC_RERAISE:
 			return rc;
 
 		case PLPGSQL_RC_EXIT:
@@ -1599,7 +1602,6 @@ exec_stmt_loop(PLpgSQL_execstate *estate, PLpgSQL_stmt_loop *stmt)
 				break;
 
 			case PLPGSQL_RC_RETURN:
-			case PLPGSQL_RC_RERAISE:
 				return rc;
 
 			default:
@@ -1663,7 +1665,6 @@ exec_stmt_while(PLpgSQL_execstate *estate, PLpgSQL_stmt_while *stmt)
 				break;
 
 			case PLPGSQL_RC_RETURN:
-			case PLPGSQL_RC_RERAISE:
 				return rc;
 
 			default:
@@ -1782,8 +1783,7 @@ exec_stmt_fori(PLpgSQL_execstate *estate, PLpgSQL_stmt_fori *stmt)
 		 */
 		rc = exec_stmts(estate, stmt->body);
 
-		if (rc == PLPGSQL_RC_RETURN ||
-			rc == PLPGSQL_RC_RERAISE)
+		if (rc == PLPGSQL_RC_RETURN)
 			break;				/* break out of the loop */
 		else if (rc == PLPGSQL_RC_EXIT)
 		{
@@ -2437,7 +2437,14 @@ exec_stmt_raise(PLpgSQL_execstate *estate, PLpgSQL_stmt_raise *stmt)
 	/* RAISE with no parameters: re-throw current exception */
 	if (stmt->condname == NULL && stmt->message == NULL &&
 		stmt->options == NIL)
-		return PLPGSQL_RC_RERAISE;
+	{
+		if (estate->cur_error != NULL)
+			ReThrowError(estate->cur_error);
+		/* oops, we're not inside a handler */
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("RAISE without parameters cannot be used outside an exception handler")));
+	}
 
 	if (stmt->condname)
 	{
@@ -2637,6 +2644,7 @@ plpgsql_estate_setup(PLpgSQL_execstate *estate,
 
 	estate->rettupdesc = NULL;
 	estate->exitlabel = NULL;
+	estate->cur_error = NULL;
 
 	estate->tuple_store = NULL;
 	if (rsi)
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index 16e073c2109..488c85bd898 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.130 2010/02/26 02:01:35 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.131 2010/08/09 02:25:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -115,8 +115,7 @@ enum
 	PLPGSQL_RC_OK,
 	PLPGSQL_RC_EXIT,
 	PLPGSQL_RC_RETURN,
-	PLPGSQL_RC_CONTINUE,
-	PLPGSQL_RC_RERAISE
+	PLPGSQL_RC_CONTINUE
 };
 
 /* ----------
@@ -699,6 +698,7 @@ typedef struct PLpgSQL_execstate
 	TupleDesc	rettupdesc;
 	char	   *exitlabel;		/* the "target" label of the current EXIT or
 								 * CONTINUE stmt, if any */
+	ErrorData  *cur_error;		/* current exception handler's error */
 
 	Tuplestorestate *tuple_store;		/* SRFs accumulate results here */
 	MemoryContext tuple_store_cxt;