Fix URL parsing to handle URLDecodeException (#149)

* Fix URL parsing to handle URLDecodeException

- Update `toUrlOrNull` method to catch all exceptions
- Add test case for invalid HTTPS URL with decoding issues

* Change catch block from `URLParserException` to `Exception` in `ResponseParser.kt` and `DavResource.kt`

Author: rfc2822

src/main/kotlin/at/bitfire/dav4jvm/ktor/DavResource.kt

@@ -41,7 +41,6 @@ import io.ktor.http.HttpHeaders
 import io.ktor.http.HttpMethod
 import io.ktor.http.HttpStatusCode
 import io.ktor.http.URLBuilder
-import io.ktor.http.URLParserException
 import io.ktor.http.Url
 import io.ktor.http.contentType
 import io.ktor.http.isSecure
@@ -643,7 +642,7 @@ open class DavResource(
                         URLBuilder(location)
                             .takeFrom(newLocation)
                             .build()
-                    } catch (e: URLParserException) {
+                    } catch (e: Exception) {
                         throw DavException("Redirected to invalid Location", cause = e)
                     }
 

src/main/kotlin/at/bitfire/dav4jvm/ktor/KtorHttpUtils.kt

@@ -14,7 +14,6 @@ import io.ktor.client.statement.HttpResponse
 import io.ktor.http.BadContentTypeFormatException
 import io.ktor.http.ContentType
 import io.ktor.http.HttpStatusCode
-import io.ktor.http.URLParserException
 import io.ktor.http.Url
 
 object KtorHttpUtils {
@@ -118,13 +117,24 @@ fun String?.toContentTypeOrNull(): ContentType? {
     }
 }
 
+/**
+ * Converts the [String] into a Ktor [Url], if possible.
+ *
+ * Differs from [io.ktor.http.parseUrl]:
+ *
+ * - `"relative".toUrlOrNull() == Url("relative")` (without host) but
+ * - `parseUrl("relative") == null` (requires host)
+ *
+ * @return the Ktor [Url], or `null` if the string couldn't be converted
+ */
 fun String?.toUrlOrNull(): Url? {
     if (this == null)
         return null
 
     return try {
         Url(this)
-    } catch (_: URLParserException) {
+    } catch (_: Exception) {
+        // parseUrl doesn't catch URLDecodeException, see https://github.com/ktorio/ktor/pull/5231
         null
     }
 }

src/main/kotlin/at/bitfire/dav4jvm/ktor/ResponseParser.kt

@@ -17,7 +17,6 @@ import at.bitfire.dav4jvm.property.webdav.ResourceType
 import at.bitfire.dav4jvm.property.webdav.WebDAV
 import io.ktor.http.HttpStatusCode
 import io.ktor.http.URLBuilder
-import io.ktor.http.URLParserException
 import io.ktor.http.Url
 import io.ktor.http.isSuccess
 import io.ktor.http.takeFrom
@@ -168,7 +167,7 @@ class ResponseParser(
 
         val urlBuilder = try {
             URLBuilder(location).takeFrom(sHref)
-        } catch (e: URLParserException) {
+        } catch (e: Exception) {
             logger.log(Level.WARNING, "Unresolvable <href> in <response>: $hrefString", e)
             return null
         }

src/test/kotlin/at/bitfire/dav4jvm/ktor/KtorHttpUtilsTest.kt

@@ -267,6 +267,11 @@ class KtorHttpUtilsTest {
         assertNull("mailto:invalid".toUrlOrNull())
     }
 
+    @Test
+    fun `toUrlOrNull with invalid HTTPS URL that can't be decoded`() {
+        assertNull("https://example.com/%f".toUrlOrNull())
+    }
+
     @Test
     fun `toUrlOrNull with valid HTTPS URL`() {
         assertEquals(