[JENKINS-75188] NPE in StandardUsernameCredentials.hashCode when has empty credentials

Fix equals and hashCode method of StandardUsernameCredentials implementation that throw NPE when stored credentials is null.

Author: nfalco79

src/main/java/com/cloudbees/jenkins/plugins/bitbucket/impl/extension/GitClientAuthenticatorExtension.java

@@ -66,7 +66,7 @@ public String getUrl() {
 
     @Override
     public int hashCode() {
-        return Objects.hash(credentials.getId(), url);
+        return Objects.hash(credentials != null ? credentials.getId() : null, credentials);
     }
 
     @Override
@@ -81,7 +81,7 @@ public boolean equals(Object obj) {
             return false;
         }
         GitClientAuthenticatorExtension other = (GitClientAuthenticatorExtension) obj;
-        return Objects.equals(credentials.getId(), other.credentials.getId())
+        return Objects.equals(credentials != null ? credentials.getId() : credentials, other.credentials != null ? other.credentials.getId() : other.credentials)
                 && Objects.equals(url, other.url);
     }
 

src/test/java/com/cloudbees/jenkins/plugins/bitbucket/impl/extension/GitClientAuthenticatorExtensionTest.java

@@ -0,0 +1,27 @@
+package com.cloudbees.jenkins.plugins.bitbucket.impl.extension;
+
+import com.cloudbees.plugins.credentials.impl.UsernamePasswordCredentialsImpl;
+import hudson.plugins.git.extensions.GitSCMExtension;
+import org.junit.jupiter.api.Test;
+import org.jvnet.hudson.test.Issue;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class GitClientAuthenticatorExtensionTest {
+
+    @Issue("JENKINS-75188")
+    @Test
+    void test_equals_hashCode() throws Exception {
+        GitSCMExtension extension = new GitClientAuthenticatorExtension("url", null);
+        assertThat(extension.hashCode()).isNotZero();
+        assertThat(extension).isEqualTo(new GitClientAuthenticatorExtension("url", null));
+
+        extension = new GitClientAuthenticatorExtension("url", new UsernamePasswordCredentialsImpl(null, "id", null, null, null));
+        assertThat(extension.hashCode()).isNotZero();
+        assertThat(extension).isNotEqualTo(new GitClientAuthenticatorExtension("url", null));
+
+        extension = new GitClientAuthenticatorExtension("url", new UsernamePasswordCredentialsImpl(null, null, null, null, null));
+        assertThat(extension.hashCode()).isNotZero();
+        assertThat(extension).isNotEqualTo(new GitClientAuthenticatorExtension("url", new UsernamePasswordCredentialsImpl(null, "some-id", null, null, null)));
+    }
+}