Fix for NPE when flushBuffer is called before getWriter

[insideaem]

A NPE is thrown when flushBuffer is called before getWriter.

[insideaem]

@rombert Could you please have a look why the build is failing? And please also review the PR?

[rombert]

@insideaem. First of all , thanks for the PR! I'm not the best person to review this but will reach out to the people who know more. I suspect they'll ask you to create a SLING jira issue with steps to reproduce, so it would be best to do that ahead of time :-) https://issues.apache.org/jira/browse/SLING

Your PR fails because we recently updated our CI to test more combinations and we haven't yet adapted all modules. I'll try to fix the scripting core build in the meantime.

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

0.0% Coverage
0.0% Duplication

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[cziegeler]

@insideaem Makes sense to prevent the NPE, please create a SLING issue first. As the code has evolved since this PR was created, please also address this for CaptureJakartaResponseWrapper.java
A test covering this case would be great

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud