Fix duplicate checker does not respect umlauts / latex free fields

CHANGELOG.md

@@ -17,6 +17,7 @@ Note that this project **does not** adhere to [Semantic Versioning](https://semv
 
 - We fixed an issue where attempting to cancel the importing/generation of an entry from id is ignored. [#10508](https://github.com/JabRef/jabref/issues/10508)
 - We fixed an issue where the preview panel showing the wrong entry (an entry that is not selected in the entry table). [#9172](https://github.com/JabRef/jabref/issues/9172)
+- We fixed an issue where the duplicate check did not take umlauts or other LaTeX-encoded characters into account. [#10744](https://github.com/JabRef/jabref/pull/10744)
 - We fixed the colors of the icon on hover for unset special fields. [#10431](https://github.com/JabRef/jabref/issues/10431)
 
 ### Removed

src/main/java/org/jabref/logic/database/DuplicateCheck.java

@@ -154,14 +154,14 @@ private static double[] compareFieldSet(final Collection<Field> fields, final Bi
     }
 
     private static int compareSingleField(final Field field, final BibEntry one, final BibEntry two) {
-        final Optional<String> optionalStringOne = one.getField(field);
-        final Optional<String> optionalStringTwo = two.getField(field);
-        if (!optionalStringOne.isPresent()) {
-            if (!optionalStringTwo.isPresent()) {
+        final Optional<String> optionalStringOne = one.getFieldLatexFree(field);
+        final Optional<String> optionalStringTwo = two.getFieldLatexFree(field);
+        if (optionalStringOne.isEmpty()) {
+            if (optionalStringTwo.isEmpty()) {
                 return EMPTY_IN_BOTH;
             }
             return EMPTY_IN_ONE;
-        } else if (!optionalStringTwo.isPresent()) {
+        } else if (optionalStringTwo.isEmpty()) {
             return EMPTY_IN_TWO;
         }
 

src/test/java/org/jabref/logic/database/DuplicateCheckTest.java

@@ -78,6 +78,14 @@ public void testDuplicateDetectionWithSameAuthor() {
         assertTrue(duplicateChecker.isDuplicate(one, two, BibDatabaseMode.BIBTEX));
     }
 
+    @Test
+    public void testDuplicateDetectionWithSameAuthorAndUmlauts() {
+        BibEntry one = new BibEntry(StandardEntryType.Article).withField(StandardField.AUTHOR, "Billy Bobä");
+        BibEntry two = new BibEntry(StandardEntryType.Article).withField(StandardField.AUTHOR, "Bill{\\\"{a}} Bob{\\\"{a}}");
+
+        assertTrue(duplicateChecker.isDuplicate(one, two, BibDatabaseMode.BIBTEX));
+    }
+
     @Test
     public void testDuplicateDetectionWithDifferentAuthors() {
         BibEntry one = new BibEntry(StandardEntryType.Article).withField(StandardField.AUTHOR, "Billy Bob");

src/test/java/org/jabref/logic/integrity/ASCIICharacterCheckerTest.java

@@ -35,11 +35,11 @@ void fieldDoesNotAcceptUnicode() {
 
     @Test
     void fieldAcceptsOnlyAsciiCharacters() {
-        String field = "";
+        StringBuilder field = new StringBuilder();
         for (int i = 32; i <= 127; i++) {
-            field += Character.toString(i);
+            field.append(Character.toString(i));
         }
-        entry.setField(StandardField.TITLE, field);
+        entry.setField(StandardField.TITLE, field.toString());
         assertEquals(Collections.emptyList(), checker.check(entry));
     }