Fix alias with schema check in Parser.parseCreateFunctionAlias()

h2/src/main/org/h2/command/Parser.java

@@ -5114,19 +5114,12 @@ public class Parser {
 
     private CreateFunctionAlias parseCreateFunctionAlias(boolean force) {
         boolean ifNotExists = readIfNotExists();
-        final boolean newAliasSameNameAsBuiltin = Function.getFunction(database, currentToken) != null;
-        String aliasName;
-        if (database.isAllowBuiltinAliasOverride() && newAliasSameNameAsBuiltin) {
-            aliasName = currentToken;
-            schemaName = session.getCurrentSchemaName();
-            read();
-        } else {
-            aliasName = readIdentifierWithSchema();
-        }
+        String aliasName = readIdentifierWithSchema();
+        final boolean newAliasSameNameAsBuiltin = Function.getFunction(database, aliasName) != null;
         if (database.isAllowBuiltinAliasOverride() && newAliasSameNameAsBuiltin) {
             // fine
         } else if (isKeyword(aliasName) ||
-                Function.getFunction(database, aliasName) != null ||
+                newAliasSameNameAsBuiltin ||
                 getAggregateType(aliasName) != null) {
             throw DbException.get(ErrorCode.FUNCTION_ALIAS_ALREADY_EXISTS_1,
                     aliasName);

h2/src/test/org/h2/test/scripts/ddl/createAlias.sql

@@ -49,3 +49,54 @@ SELECT ALIAS_NAME, JAVA_CLASS, JAVA_METHOD, DATA_TYPE, COLUMN_COUNT, RETURNS_RES
 
 DROP ALIAS MY_SQRT;
 > ok
+
+CREATE SCHEMA TEST_SCHEMA;
+> ok
+
+CREATE ALIAS TRUNC FOR "java.lang.Math.floor(double)";
+> exception
+
+CREATE ALIAS PUBLIC.TRUNC FOR "java.lang.Math.floor(double)";
+> exception
+
+CREATE ALIAS TEST_SCHEMA.TRUNC FOR "java.lang.Math.round(double)";
+> exception
+
+SET BUILTIN_ALIAS_OVERRIDE=1;
+> ok
+
+CREATE ALIAS TRUNC FOR "java.lang.Math.floor(double)";
+> ok
+
+DROP ALIAS TRUNC;
+> ok
+
+CREATE ALIAS PUBLIC.TRUNC FOR "java.lang.Math.floor(double)";
+> ok
+
+CREATE ALIAS TEST_SCHEMA.TRUNC FOR "java.lang.Math.round(double)";
+> ok
+
+SELECT PUBLIC.TRUNC(1.5);
+>> 1.0
+
+SELECT PUBLIC.TRUNC(-1.5);
+>> -2.0
+
+SELECT TEST_SCHEMA.TRUNC(1.5);
+>> 2
+
+SELECT TEST_SCHEMA.TRUNC(-1.5);
+>> -1
+
+DROP ALIAS PUBLIC.TRUNC;
+> ok
+
+DROP ALIAS TEST_SCHEMA.TRUNC;
+> ok
+
+SET BUILTIN_ALIAS_OVERRIDE=0;
+> ok
+
+DROP SCHEMA TEST_SCHEMA RESTRICT;
+> ok