Merge pull request #783 from spotify/mattbrown/fix-npe-multiauth

fix NPE in MultiRegistryAuthSupplier

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Changelog
 
+## 8.7.1
+
+### Bugfixes
+
+Fix NPE in MultiRegistryAuthSupplier ([783][])
+
+[783]: https://github.com/spotify/docker-client/pull/783
+
 ## 8.7.0
 
 Released June 5, 2017

src/main/java/com/spotify/docker/client/auth/MultiRegistryAuthSupplier.java

@@ -75,7 +75,9 @@ public RegistryConfigs authForBuild() throws DockerException {
     // have precedence
     for (RegistryAuthSupplier supplier : Lists.reverse(suppliers)) {
       final RegistryConfigs configs = supplier.authForBuild();
-      allConfigs.putAll(configs.configs());
+      if (configs != null && configs.configs() != null) {
+        allConfigs.putAll(configs.configs());
+      }
     }
     return RegistryConfigs.create(allConfigs);
   }

src/main/java/com/spotify/docker/client/auth/RegistryAuthSupplier.java

@@ -38,6 +38,8 @@ public interface RegistryAuthSupplier {
    * Returns a RegistryAuth object that is valid for a Docker Swarm context [i.e. not tied
    * to specific image]. It's unnecessary if it's not planned to use this AuthSupplier to pull
    * images for Swarm.
+   *
+   * @return the RegistryAuth to use in Swarn, or else {@code null} for no authentication info
    */
   RegistryAuth authForSwarm() throws DockerException;
 

src/test/java/com/spotify/docker/client/auth/MultiRegistryAuthSupplierTest.java

@@ -111,7 +111,6 @@ public void testAuthForBuild() throws Exception {
         "b", auth2
     )));
 
-    //
     when(supplier2.authForBuild()).thenReturn(RegistryConfigs.create(ImmutableMap.of(
         "b", auth3,
         "c", auth4
@@ -124,4 +123,29 @@ public void testAuthForBuild() throws Exception {
         hasEntry("c", auth4)
     ));
   }
+
+  /**
+   * Test what happens if one of the Suppliers returns null for authForBuild().
+   */
+  @Test
+  public void testAuthForBuild_ReturnsNull() throws Exception {
+
+    when(supplier1.authForBuild()).thenReturn(null);
+
+    final RegistryConfigs registryConfigs = RegistryConfigs.create(ImmutableMap.of(
+        "a",
+        RegistryAuth.builder()
+            .username("1")
+            .serverAddress("a")
+            .build(),
+        "b",
+        RegistryAuth.builder()
+            .username("2")
+            .serverAddress("b")
+            .build()
+    ));
+    when(supplier2.authForBuild()).thenReturn(registryConfigs);
+
+    assertThat(multiSupplier.authForBuild(), is(registryConfigs));
+  }
 }