From: Peter Eisentraut <peter@eisentraut.org>
Date: Sat, 28 Mar 2026 14:44:13 +0000 (+0100)
Subject: Make cast functions from jsonb error safe
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=10e4d8aaf46fb46b8b78e026560b68af84a6495b;p=thirdparty%2Fpostgresql.git

Make cast functions from jsonb error safe

This adjusts cast functions from jsonb to other types to support soft
errors.  This just involves some refactoring of the underlying helper
functions to use ereturn.

This is in preparation for a future feature where conversion errors in
casts can be caught.

Author: jian he <jian.universality@gmail.com>
Reviewed-by: Amul Sul <sulamul@gmail.com>
Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CADkLM%3Dfv1JfY4Ufa-jcwwNbjQixNViskQ8jZu3Tz_p656i_4hQ%40mail.gmail.com
---

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1b1a8f301f2..864c5ac1c85 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1785,8 +1785,8 @@ JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res)
 /*
  * Emit correct, translatable cast error message
  */
-static void
-cannotCastJsonbValue(enum jbvType type, const char *sqltype)
+static Datum
+cannotCastJsonbValue(enum jbvType type, const char *sqltype, Node *escontext)
 {
 	static const struct
 	{
@@ -1807,12 +1807,13 @@ cannotCastJsonbValue(enum jbvType type, const char *sqltype)
 
 	for (i = 0; i < lengthof(messages); i++)
 		if (messages[i].type == type)
-			ereport(ERROR,
+			ereturn(escontext, (Datum) 0,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg(messages[i].msg, sqltype)));
 
 	/* should be unreachable */
 	elog(ERROR, "unknown jsonb type: %d", (int) type);
+	return (Datum) 0;
 }
 
 Datum
@@ -1822,7 +1823,7 @@ jsonb_bool(PG_FUNCTION_ARGS)
 	JsonbValue	v;
 
 	if (!JsonbExtractScalar(&in->root, &v))
-		cannotCastJsonbValue(v.type, "boolean");
+		return cannotCastJsonbValue(v.type, "boolean", fcinfo->context);
 
 	if (v.type == jbvNull)
 	{
@@ -1831,7 +1832,7 @@ jsonb_bool(PG_FUNCTION_ARGS)
 	}
 
 	if (v.type != jbvBool)
-		cannotCastJsonbValue(v.type, "boolean");
+		return cannotCastJsonbValue(v.type, "boolean", fcinfo->context);
 
 	PG_FREE_IF_COPY(in, 0);
 
@@ -1846,7 +1847,7 @@ jsonb_numeric(PG_FUNCTION_ARGS)
 	Numeric		retValue;
 
 	if (!JsonbExtractScalar(&in->root, &v))
-		cannotCastJsonbValue(v.type, "numeric");
+		return cannotCastJsonbValue(v.type, "numeric", fcinfo->context);
 
 	if (v.type == jbvNull)
 	{
@@ -1855,7 +1856,7 @@ jsonb_numeric(PG_FUNCTION_ARGS)
 	}
 
 	if (v.type != jbvNumeric)
-		cannotCastJsonbValue(v.type, "numeric");
+		return cannotCastJsonbValue(v.type, "numeric", fcinfo->context);
 
 	/*
 	 * v.val.numeric points into jsonb body, so we need to make a copy to
@@ -1876,7 +1877,7 @@ jsonb_int2(PG_FUNCTION_ARGS)
 	Datum		retValue;
 
 	if (!JsonbExtractScalar(&in->root, &v))
-		cannotCastJsonbValue(v.type, "smallint");
+		return cannotCastJsonbValue(v.type, "smallint", fcinfo->context);
 
 	if (v.type == jbvNull)
 	{
@@ -1885,7 +1886,7 @@ jsonb_int2(PG_FUNCTION_ARGS)
 	}
 
 	if (v.type != jbvNumeric)
-		cannotCastJsonbValue(v.type, "smallint");
+		return cannotCastJsonbValue(v.type, "smallint", fcinfo->context);
 
 	retValue = DirectFunctionCall1(numeric_int2,
 								   NumericGetDatum(v.val.numeric));
@@ -1903,7 +1904,7 @@ jsonb_int4(PG_FUNCTION_ARGS)
 	Datum		retValue;
 
 	if (!JsonbExtractScalar(&in->root, &v))
-		cannotCastJsonbValue(v.type, "integer");
+		return cannotCastJsonbValue(v.type, "integer", fcinfo->context);
 
 	if (v.type == jbvNull)
 	{
@@ -1912,7 +1913,7 @@ jsonb_int4(PG_FUNCTION_ARGS)
 	}
 
 	if (v.type != jbvNumeric)
-		cannotCastJsonbValue(v.type, "integer");
+		return cannotCastJsonbValue(v.type, "integer", fcinfo->context);
 
 	retValue = DirectFunctionCall1(numeric_int4,
 								   NumericGetDatum(v.val.numeric));
@@ -1930,7 +1931,7 @@ jsonb_int8(PG_FUNCTION_ARGS)
 	Datum		retValue;
 
 	if (!JsonbExtractScalar(&in->root, &v))
-		cannotCastJsonbValue(v.type, "bigint");
+		return cannotCastJsonbValue(v.type, "bigint", fcinfo->context);
 
 	if (v.type == jbvNull)
 	{
@@ -1939,7 +1940,7 @@ jsonb_int8(PG_FUNCTION_ARGS)
 	}
 
 	if (v.type != jbvNumeric)
-		cannotCastJsonbValue(v.type, "bigint");
+		return cannotCastJsonbValue(v.type, "bigint", fcinfo->context);
 
 	retValue = DirectFunctionCall1(numeric_int8,
 								   NumericGetDatum(v.val.numeric));
@@ -1957,7 +1958,7 @@ jsonb_float4(PG_FUNCTION_ARGS)
 	Datum		retValue;
 
 	if (!JsonbExtractScalar(&in->root, &v))
-		cannotCastJsonbValue(v.type, "real");
+		return cannotCastJsonbValue(v.type, "real", fcinfo->context);
 
 	if (v.type == jbvNull)
 	{
@@ -1966,7 +1967,7 @@ jsonb_float4(PG_FUNCTION_ARGS)
 	}
 
 	if (v.type != jbvNumeric)
-		cannotCastJsonbValue(v.type, "real");
+		return cannotCastJsonbValue(v.type, "real", fcinfo->context);
 
 	retValue = DirectFunctionCall1(numeric_float4,
 								   NumericGetDatum(v.val.numeric));
@@ -1984,7 +1985,7 @@ jsonb_float8(PG_FUNCTION_ARGS)
 	Datum		retValue;
 
 	if (!JsonbExtractScalar(&in->root, &v))
-		cannotCastJsonbValue(v.type, "double precision");
+		return cannotCastJsonbValue(v.type, "double precision", fcinfo->context);
 
 	if (v.type == jbvNull)
 	{
@@ -1993,7 +1994,7 @@ jsonb_float8(PG_FUNCTION_ARGS)
 	}
 
 	if (v.type != jbvNumeric)
-		cannotCastJsonbValue(v.type, "double precision");
+		return cannotCastJsonbValue(v.type, "double precision", fcinfo->context);
 
 	retValue = DirectFunctionCall1(numeric_float8,
 								   NumericGetDatum(v.val.numeric));