If Meteor.http.call JSON-ifies the request body, default the Content-Type to

application/json.

This matches our heuristic for deciding whether to parse responses as JSON.

packages/http/httpcall_client.js

@@ -20,9 +20,13 @@ Meteor.http = Meteor.http || {};
 
     method = (method || "").toUpperCase();
 
+    var headers = {};
+
     var content = options.content;
-    if (options.data)
+    if (options.data) {
       content = JSON.stringify(options.data);
+      headers['Content-Type'] = 'application/json';
+    }
 
     var params_for_url, params_for_body;
     if (content || method === "GET" || method === "HEAD")
@@ -51,6 +55,8 @@ Meteor.http = Meteor.http || {};
       content = Meteor.http._encodeParams(params_for_body);
     }
 
+    _.extend(headers, options.headers || {});
+
     ////////// Callback wrapping //////////
 
     // wrap callback to always return a result object, and always
@@ -84,9 +90,8 @@ Meteor.http = Meteor.http || {};
 
       xhr.open(method, url, true, username, password);
 
-      if (options.headers)
-        for (var k in options.headers)
-          xhr.setRequestHeader(k, options.headers[k]);
+      for (var k in headers)
+        xhr.setRequestHeader(k, headers[k]);
 
 
       // setup timeout

packages/http/httpcall_server.js

@@ -27,9 +27,13 @@ Meteor.http = Meteor.http || {};
 
     var url_parts = url_util.parse(url);
 
+    var headers = {};
+
     var content = options.content;
-    if (options.data)
+    if (options.data) {
       content = JSON.stringify(options.data);
+      headers['Content-Type'] = 'application/json';
+    }
 
 
     var params_for_url, params_for_body;
@@ -42,9 +46,6 @@ Meteor.http = Meteor.http || {};
       url_parts.protocol+"//"+url_parts.host+url_parts.pathname,
       url_parts.search, options.query, params_for_url);
 
-
-    var headers = {};
-
     if (options.auth) {
       if (options.auth.indexOf(':') < 0)
         throw new Error('auth option should be of the form "username:password"');

packages/http/httpcall_tests.js

@@ -222,6 +222,20 @@ testAsyncMulti("httpcall - methods", [
         test.equal(result.statusCode, 200);
         var data = result.data;
         test.equal(data.body, {greeting: "Hello World!"});
+        test.equal(data.headers['content-type'], 'application/json');
+      }));
+
+    Meteor.http.call(
+      "POST", url_prefix()+"/data-test-explicit",
+      { data: {greeting: "Hello World!"},
+        headers: {'Content-Type': 'text/stupid'} },
+      expect(function(error, result) {
+        test.isFalse(error);
+        test.isTrue(result);
+        test.equal(result.statusCode, 200);
+        var data = result.data;
+        test.equal(data.body, {greeting: "Hello World!"});
+        test.equal(data.headers['content-type'], 'text/stupid');
       }));
   }
 ]);