Additional fallback handling of context selection in unparsable sources

recaf-core/src/main/java/software/coley/recaf/services/source/AstRangeMapper.java

@@ -12,6 +12,7 @@
 import org.openrewrite.java.tree.Space;
 import org.openrewrite.marker.Marker;
 import org.openrewrite.marker.Range;
+import software.coley.collections.Unchecked;
 import software.coley.recaf.analytics.logging.DebuggingLogger;
 import software.coley.recaf.analytics.logging.Logging;
 import software.coley.recaf.util.StringDiff;
@@ -62,7 +63,7 @@ public static SortedMap<Range, Tree> computeRangeToTreeMapping(@Nonnull Tree tre
 			}
 			return cmp;
 		});
-		DiffHelper helper = backingText == null ? null : new DiffHelper(backingText, tree);
+		DiffHelper helper = backingText == null ? null : Unchecked.getOr(() -> new DiffHelper(backingText, tree), null);
 		PositionPrintOutputCapture ppoc = new PositionPrintOutputCapture(helper);
 		JavaPrinter<ExecutionContext> printer = new JavaPrinter<>() {
 			final JavaPrinter<ExecutionContext> spacePrinter = new JavaPrinter<>();
@@ -80,7 +81,10 @@ public J visit(@Nullable Tree tree, @Nonnull PrintOutputCapture<ExecutionContext
 				spacePrinter.visitSpace(t.getPrefix(), Space.Location.ANY, prefix);
 
 				Range.Position startPosition = new Range.Position(prefix.posInBacking, prefix.line, prefix.column);
-				t = super.visit(tree, outputCapture);
+				t = Unchecked.getOr(() ->super.visit(tree, outputCapture), null);
+				if (t == null) {
+					return null;
+				}
 				Range.Position endPosition = new Range.Position(ppoc.posInBacking, ppoc.line, ppoc.column);
 				Range range = new Range(randomId(), startPosition, endPosition);
 				rangeMap.put(range, t);