fix issues

Author: krusche

server/src/main/java/de/tum/cit/aet/thesis/controller/ThesisController.java

@@ -258,14 +258,14 @@ public ResponseEntity<ThesisDto> updateThesisInfo(
 
 		thesis = thesisService.updateThesisInfo(
 				thesis,
-				RequestValidator.validateStringMaxLength(payload.abstractText(), StringLimits.UNLIMITED_TEXT.getLimit()),
-				RequestValidator.validateStringMaxLength(payload.infoText(), StringLimits.UNLIMITED_TEXT.getLimit())
+				RequestValidator.validateStringMaxLengthAllowNull(payload.abstractText(), StringLimits.UNLIMITED_TEXT.getLimit()),
+				RequestValidator.validateStringMaxLengthAllowNull(payload.infoText(), StringLimits.UNLIMITED_TEXT.getLimit())
 		);
 
 		thesis = thesisService.updateThesisTitles(
 				thesis,
-				RequestValidator.validateStringMaxLength(payload.primaryTitle(), StringLimits.THESIS_TITLE.getLimit()),
-				RequestValidator.validateNotNull(payload.secondaryTitles())
+				RequestValidator.validateStringMaxLengthAllowNull(payload.primaryTitle(), StringLimits.THESIS_TITLE.getLimit()),
+				payload.secondaryTitles()
 		);
 
 		return ResponseEntity.ok(ThesisDto.fromThesisEntity(thesis, thesis.hasAdvisorAccess(currentUser), thesis.hasStudentAccess(currentUser)));

server/src/main/java/de/tum/cit/aet/thesis/service/ThesisService.java

@@ -322,8 +322,8 @@ public Thesis updateThesisInfo(
 			String infoText
 	) {
 		currentUserProvider().assertCanAccessResearchGroup(thesis.getResearchGroup());
-		thesis.setAbstractField(abstractText);
-		thesis.setInfo(infoText);
+		thesis.setAbstractField(abstractText != null ? abstractText : "");
+		thesis.setInfo(infoText != null ? infoText : "");
 
 		thesis = thesisRepository.save(thesis);
 
@@ -339,11 +339,15 @@ public Thesis updateThesisTitles(
 			Map<String, String> titles
 	) {
 		currentUserProvider().assertCanAccessResearchGroup(thesis.getResearchGroup());
-		thesis.setMetadata(new ThesisMetadata(
-				titles,
-				thesis.getMetadata().credits()
-		));
-		thesis.setTitle(primaryTitle);
+		if (titles != null) {
+			thesis.setMetadata(new ThesisMetadata(
+					titles,
+					thesis.getMetadata().credits()
+			));
+		}
+		if (primaryTitle != null) {
+			thesis.setTitle(primaryTitle);
+		}
 
 		thesis = thesisRepository.save(thesis);