Improve error message when submittabiliy expression is missing for SR

The error message should include the name of the parameter that is
expected to be set.

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: Ida8af0d1d3bbd8317de9ac9b261793a5493527d2
diff --git a/java/com/google/gerrit/server/project/ProjectConfig.java b/java/com/google/gerrit/server/project/ProjectConfig.java
index 8f0b535..0d34dee 100644
--- a/java/com/google/gerrit/server/project/ProjectConfig.java
+++ b/java/com/google/gerrit/server/project/ProjectConfig.java
@@ -957,7 +957,9 @@
       if (blockExpr == null) {
         error(
             String.format(
-                "Submit requirement '%s' does not define a submittability expression.", name));
+                "Setting a submittability expression for submit requirement '%s' is required:"
+                    + " Missing %s.%s.%s",
+                name, SUBMIT_REQUIREMENT, name, KEY_SR_SUBMITTABILITY_EXPRESSION));
         continue;
       }
 
diff --git a/javatests/com/google/gerrit/acceptance/server/project/SubmitRequirementsValidationIT.java b/javatests/com/google/gerrit/acceptance/server/project/SubmitRequirementsValidationIT.java
index 4675bc0..182a741 100644
--- a/javatests/com/google/gerrit/acceptance/server/project/SubmitRequirementsValidationIT.java
+++ b/javatests/com/google/gerrit/acceptance/server/project/SubmitRequirementsValidationIT.java
@@ -170,8 +170,12 @@
         r,
         "Invalid project configuration",
         String.format(
-            "project.config: Submit requirement '%s' does not define a submittability expression.",
-            submitRequirementName));
+            "project.config: Setting a submittability expression for submit requirement '%s' is"
+                + " required: Missing %s.%s.%s",
+            submitRequirementName,
+            ProjectConfig.SUBMIT_REQUIREMENT,
+            submitRequirementName,
+            ProjectConfig.KEY_SR_SUBMITTABILITY_EXPRESSION));
   }
 
   private void fetchRefsMetaConfig() throws Exception {
diff --git a/javatests/com/google/gerrit/server/project/ProjectConfigTest.java b/javatests/com/google/gerrit/server/project/ProjectConfigTest.java
index 9df59c2..48ef85d8 100644
--- a/javatests/com/google/gerrit/server/project/ProjectConfigTest.java
+++ b/javatests/com/google/gerrit/server/project/ProjectConfigTest.java
@@ -330,8 +330,9 @@
     assertThat(cfg.getValidationErrors()).hasSize(1);
     assertThat(Iterables.getOnlyElement(cfg.getValidationErrors()).getMessage())
         .isEqualTo(
-            "project.config: Submit requirement 'code-review' does not define a submittability"
-                + " expression.");
+            "project.config: Setting a submittability expression for submit requirement"
+                + " 'code-review' is required: Missing"
+                + " submit-requirement.code-review.submittableIf");
   }
 
   @Test