Fixes #555. Guard against null ptr

parrt · parrt · commit 4fa1cc83d9ae · 2022-05-21T11:15:00.000-07:00
Signed-off-by: Terence Parr &lt;parrt@antlr.org&gt;
diff --git a/src/main/java/org/antlr/intellij/plugin/preview/InputPanel.java b/src/main/java/org/antlr/intellij/plugin/preview/InputPanel.java
@@ -234,7 +234,7 @@ public void documentChanged(DocumentEvent event) {
 
 	public void grammarFileSaved() {
 		clearParseErrors();
-		if ( previewState.startRuleName!=null ) {
+		if ( previewState!=null && previewState.startRuleName!=null ) {
 			setStartRuleName(previewState.grammarFile, previewState.startRuleName);
 		}
 		else {

Original file line number	Diff line number	Diff line change
`@@ -234,7 +234,7 @@ public void documentChanged(DocumentEvent event) {`
`234`	`234`
`235`	`235`	`public void grammarFileSaved() {`
`236`	`236`	`clearParseErrors();`
`237`		`- if ( previewState.startRuleName!=null ) {`
	`237`	`+ if ( previewState!=null && previewState.startRuleName!=null ) {`
`238`	`238`	`setStartRuleName(previewState.grammarFile, previewState.startRuleName);`
`239`	`239`	`}`
`240`	`240`	`else {`