Issue #696: browser-engine-system: Clear "X-Requested-With" header when loading URLs.

components/browser/engine-system/src/main/java/mozilla/components/browser/engine/system/SystemEngineSession.kt

@@ -13,6 +13,14 @@ import kotlinx.coroutines.experimental.launch
 import mozilla.components.concept.engine.Settings
 import mozilla.components.concept.engine.request.RequestInterceptor
 
+internal val additionalHeaders = mapOf(
+    // For every request WebView sends a "X-requested-with" header with the package name of the
+    // application. We can't really prevent that but we can at least send an empty value.
+    // Unfortunately the additional headers will not be propagated to subsequent requests
+    // (e.g. redirects). See issue #696.
+    "X-Requested-With" to ""
+)
+
 /**
  * WebView-based EngineSession implementation.
  */
@@ -34,7 +42,7 @@ class SystemEngineSession(private val defaultSettings: Settings? = null) : Engin
             scheduledLoad = ScheduledLoad(url)
         } else {
             view?.get()?.currentUrl = url
-            internalView.loadUrl(url)
+            internalView.loadUrl(url, additionalHeaders)
         }
     }
 

components/browser/engine-system/src/main/java/mozilla/components/browser/engine/system/SystemEngineView.kt

@@ -69,7 +69,7 @@ class SystemEngineView @JvmOverloads constructor(
         }
 
         internalSession.scheduledLoad.url?.let {
-            currentWebView.loadUrl(it)
+            currentWebView.loadUrl(it, additionalHeaders)
             internalSession.scheduledLoad = ScheduledLoad()
         }
     }

components/browser/engine-system/src/test/java/mozilla/components/browser/engine/system/SystemEngineSessionTest.kt

@@ -52,16 +52,31 @@ class SystemEngineSessionTest {
 
     @Test
     fun testLoadUrl() {
+        var loadedUrl: String? = null
+        var loadHeaders: Map<String, String>? = null
+
         val engineSession = spy(SystemEngineSession())
-        val webView = mock(WebView::class.java)
+        val webView = spy(object : WebView(RuntimeEnvironment.application) {
+            override fun loadUrl(url: String?, additionalHttpHeaders: MutableMap<String, String>?) {
+                loadedUrl = url
+                loadHeaders = additionalHttpHeaders
+            }
+        })
 
         engineSession.loadUrl("")
         verify(webView, never()).loadUrl(anyString())
 
         `when`(engineSession.currentView()).thenReturn(webView)
 
         engineSession.loadUrl("http://mozilla.org")
-        verify(webView).loadUrl("http://mozilla.org")
+        verify(webView).loadUrl(eq("http://mozilla.org"), any())
+
+        assertEquals("http://mozilla.org", loadedUrl)
+
+        assertNotNull(loadHeaders)
+        assertEquals(1, loadHeaders!!.size)
+        assertTrue(loadHeaders!!.containsKey("X-Requested-With"))
+        assertEquals("", loadHeaders!!["X-Requested-With"])
     }
 
     @Test