Suppress decoding error for resource path

Closes gh-23463

spring-webflux/src/main/java/org/springframework/web/reactive/resource/PathResourceResolver.java

@@ -203,6 +203,9 @@ public class PathResourceResolver extends AbstractResourceResolver {
 					return true;
 				}
 			}
+			catch (IllegalArgumentException ex) {
+				// May not be possible to decode...
+			}
 			catch (UnsupportedEncodingException ex) {
 				// Should never happen...
 			}

spring-webflux/src/main/java/org/springframework/web/reactive/resource/ResourceWebHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -468,7 +468,10 @@ public class ResourceWebHandler implements WebHandler, InitializingBean {
 					return true;
 				}
 			}
-			catch (IllegalArgumentException | UnsupportedEncodingException ex) {
+			catch (IllegalArgumentException ex) {
+				// May not be possible to decode...
+			}
+			catch (UnsupportedEncodingException ex) {
 				// Should never happen...
 			}
 		}

spring-webflux/src/test/java/org/springframework/web/reactive/resource/PathResourceResolverTests.java

@@ -109,6 +109,13 @@ public class PathResourceResolverTests {
 		assertNull(actual);
 	}
 
+	@Test // gh-23463
+	public void ignoreInvalidEscapeSequence() throws IOException {
+		UrlResource location = new UrlResource(getClass().getResource("./test/"));
+		Resource resource = location.createRelative("test%file.txt");
+		assertTrue(this.resolver.checkResource(resource, location));
+	}
+
 	@Test
 	public void checkResourceWithAllowedLocations() {
 		this.resolver.setAllowedLocations(