Merge pull request rust-lang#3142 from topecongiro/issue-3139

Do not remove path disambiugator inside macro

Author: nrc

src/types.rs

@@ -229,7 +229,9 @@ fn rewrite_segment(
                     .chain(data.bindings.iter().map(|x| SegmentParam::Binding(&*x)))
                     .collect::<Vec<_>>();
 
-                let separator = if path_context == PathContext::Expr {
+                let force_separator =
+                    context.inside_macro() && context.snippet(data.span).starts_with("::");
+                let separator = if path_context == PathContext::Expr || force_separator {
                     "::"
                 } else {
                     ""

tests/source/type.rs

@@ -121,3 +121,11 @@ fn issue3117() {
         }
     }
 }
+
+// #3139
+fn issue3139() {
+    assert_eq!(
+        to_json_value(&None ::  <i32>).unwrap(),
+        json!(  { "test": None  ::  <i32> }  )
+    );
+}

tests/target/type.rs

@@ -120,3 +120,11 @@ fn issue3117() {
         }
     }
 }
+
+// #3139
+fn issue3139() {
+    assert_eq!(
+        to_json_value(&None::<i32>).unwrap(),
+        json!({ "test": None::<i32> })
+    );
+}