Fixes mbj4668#690: Stop uses expanding if import circular dependency exists

Author: fredgan

pyang/statements.py

@@ -1491,7 +1491,7 @@ def v_expand_1_uses(ctx, stmt):
     if getattr(stmt, 'is_grammatically_valid', None) is False:
         return
 
-    if stmt.i_grouping is None:
+    if not hasattr(stmt, 'i_grouping') or stmt.i_grouping is None:
         return
 
     # possibly expand any uses within the grouping

test/test_issues/test_i690/Makefile

@@ -0,0 +1,4 @@
+test: test1
+
+test1:
+	-$(PYANG) test.yang --print-error-code 2>&1 | diff main.expect -

test/test_issues/test_i690/main.expect

@@ -0,0 +1 @@
+test2.yang:9: error: CIRCULAR_DEPENDENCY

test/test_issues/test_i690/test.yang

@@ -0,0 +1,32 @@
+module test {
+
+  yang-version "1";
+
+  namespace "http://test";
+
+  prefix test;
+
+  import test2 {
+    prefix test2;
+  }
+
+
+  organization "x";
+  contact "x";
+  description "x";
+
+  revision 2017-04-21 {
+    description "1st revision.";
+  }
+
+  grouping testgrouping1 {
+   leaf test {
+    type string;
+   }
+  }
+  grouping testgrouping {
+    uses testgrouping1;
+  }
+
+  uses test2:testgrouping;
+}

test/test_issues/test_i690/test2.yang

@@ -0,0 +1,29 @@
+module test2 {
+
+  yang-version "1";
+
+  namespace "http://test2";
+
+  prefix test2;
+
+  import test {
+    prefix test;
+  }
+
+  organization "x";
+  contact "x";
+  description "x";
+
+  revision 2017-04-21 {
+    description "1st revision.";
+  }
+
+  container one {
+    leaf two {
+      type string;
+    }
+  }
+  grouping testgrouping {
+    uses test:testgrouping;
+  }
+}