make cache file length configurable, ensure it's below 140 - encrypte…

…d ext4 seems to have a 143 byte limit, see #23850

git-svn-id: https://josm.openstreetmap.de/svn/trunk@19211 0c6e7542-c601-0410-84e7-c038aed88b3b

src/org/openstreetmap/josm/io/CachedFile.java

@@ -484,8 +484,10 @@ private File checkLocal(URL url) throws IOException {
         }
 
         String a = urlStr.replaceAll("[^A-Za-z0-9_.-]", "_");
-        if (a.length() > 120) {
-            a = a.substring(0, 100) + "_" + Utils.md5Hex(urlStr);
+        /* size 11: prefix mirror_ and suffix .tmp */
+        Integer maxFileLength = Config.getPref().getInt("cache.filename.maxlength", 140)-11;
+        if (a.length() > maxFileLength) {
+            a = a.substring(0, maxFileLength-33) + "_" + Utils.md5Hex(urlStr);
         }
         String localPath = "mirror_" + a;
         localPath = truncatePath(destDir, localPath);