Add descriptor commit validation regression coverage

package/package/src/main/java/net/runelite/pluginhub/packager/Plugin.java

@@ -248,7 +248,7 @@ public Plugin(File pluginCommitDescriptor) throws IOException, DisabledPluginExc
 		}
 
 		commit = (String) cd.remove("commit");
-		if (!COMMIT_TEST.matcher(commit).matches())
+		if (commit == null || !COMMIT_TEST.matcher(commit).matches())
 		{
 			throw PluginBuildException.of(internalName, "commit must be a full 40 character sha1sum")
 				.withFileLine(pluginCommitDescriptor, "commit=" + commit);

package/package/src/test/java/net/runelite/pluginhub/packager/PluginTest.java

@@ -53,6 +53,23 @@ public void testInternalNameChecks() throws IOException, DisabledPluginException
 		}
 	}
 
+	@Test
+	public void testCommitIsRequired() throws DisabledPluginException, IOException
+	{
+		try
+		{
+			newPlugin("test", "" +
+				"repository=https://github.com/runelite/example-plugin.git\n");
+			Assert.fail();
+		}
+		catch (PluginBuildException e)
+		{
+			log.info("ok: ", e);
+			assertContains(e.getMessage(), "commit must be a full 40 character sha1sum");
+			assertContains(e.getHelpText(), "commit=null");
+		}
+	}
+
 	@Test
 	public void testCommitMustBeComplete() throws DisabledPluginException, IOException
 	{

plugins/grand-flip-out

@@ -0,0 +1,3 @@
+repository=https://github.com/Tunatroll/grand-flip-out.git
+commit=1d2649de4cb8cdac32a771b6e6fcb9396e32fdc1
+warning=This plugin submits your IP address to a 3rd-party server not controlled or verified by RuneLite developers.