ESQL: Fix the FIRST function name (#132503)

nik9000 · web-flow · commit fd057bf6aab7 · 2025-08-06T11:51:48.000-04:00
I made a mistake in #132469
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/parser/ExpressionBuilder.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/parser/ExpressionBuilder.java
@@ -643,7 +643,11 @@ public String visitFunctionName(EsqlBaseParser.FunctionNameContext ctx) {
     }
 
     private String functionName(EsqlBaseParser.FunctionNameContext ctx) {
-        TerminalNode first = ctx.LAST();
+        /*
+         * FIRST and LAST are valid function names AND tokens used in `NULLS LAST`.
+         * So we have to have special handling for them here.
+         */
+        TerminalNode first = ctx.FIRST();
         if (first != null) {
             return first.getText();
         }

Original file line number	Diff line number	Diff line change
`@@ -643,7 +643,11 @@ public String visitFunctionName(EsqlBaseParser.FunctionNameContext ctx) {`
`643`	`643`	`}`
`644`	`644`
`645`	`645`	`private String functionName(EsqlBaseParser.FunctionNameContext ctx) {`
`646`		`- TerminalNode first = ctx.LAST();`
	`646`	`+ /*`
	`647`	+ * FIRST and LAST are valid function names AND tokens used in `NULLS LAST`.
	`648`	`+ * So we have to have special handling for them here.`
	`649`	`+ */`
	`650`	`+ TerminalNode first = ctx.FIRST();`
`647`	`651`	`if (first != null) {`
`648`	`652`	`return first.getText();`
`649`	`653`	`}`