Bugfix: picture name suffixes were malformed on export and thus could not be re-imported.

src/androidTest/java/de/dennisguse/opentracks/util/FileUtilsTest.java

@@ -60,10 +60,15 @@ public class FileUtilsTest extends TestCase {
      */
     public void testSanitizeFileName() {
         String name = "Swim\10ming-^across:/the/ pacific (ocean).";
-        String expected = "Swim_ming-^across_the_ pacific (ocean)_";
+        String expected = "Swim_ming-^across_the_ pacific (ocean).";
         assertEquals(expected, FileUtils.sanitizeFileName(name));
     }
 
+    public void testSanitizeFileNameWithSuffix() {
+        String name = "FileName.jpeg";
+        assertEquals(name, FileUtils.sanitizeFileName(name));
+    }
+
     /**
      * Tests {@link FileUtils#sanitizeFileName(String)} with i18n characters (in Chinese and Russian).
      * Verifies that they are allowed.

src/main/java/de/dennisguse/opentracks/util/FileUtils.java

@@ -204,12 +204,13 @@ public class FileUtils {
      *
      * @param name name
      */
+    // TODO Check if this function is still needed.
     public static String sanitizeFileName(String name) {
         StringBuilder builder = new StringBuilder(name.length());
         for (int i = 0; i < name.length(); i++) {
             int codePoint = name.codePointAt(i);
             char character = name.charAt(i);
-            if (Character.isLetterOrDigit(character) || codePoint > 127 || isSpecialFat32(character)) {
+            if (Character.isLetterOrDigit(character) || codePoint > 127 || isSpecialFat32(character) || character == '.') {
                 builder.appendCodePoint(codePoint);
             } else {
                 builder.append("_");