Issue #1505 - Rebuild application version string

To respond dynamically to the pref change, the mAppVersion string needs
to be rebuilt.
Includes some minor improvements for corner cases and removes leftover
b2g junk.

netwerk/protocol/http/nsHttpHandler.cpp

@@ -310,28 +310,9 @@ nsHttpHandler::Init()
         }
         mAppName.StripChars(R"( ()<>@,;:\"/[]?={})");
     }
-    
-    nsCString dynamicBuildID;
-    if (appInfo) {
-      appInfo->GetPlatformBuildID(dynamicBuildID);
-      if (dynamicBuildID.Length() > 8 )
-        dynamicBuildID.Left(dynamicBuildID, 8);
-    }
 
-    if (mAppVersionIsBuildID) {
-      // Override BuildID
-      mAppVersion.AssignLiteral(MOZ_UA_BUILDID);
-    } else if (appInfo) {
-      appInfo->GetVersion(mAppVersion);
-    } else {
-      // Fall back to platform if appInfo is unavailable
-      mAppVersion.AssignLiteral(MOZILLA_UAVERSION);
-    }
+    BuildAppVersion();    
 
-    // If there's no override set, set it to the dynamic BuildID
-    if (mAppVersion.IsEmpty())
-      mAppVersion.Assign(dynamicBuildID);
-        
     mSessionStartTime = NowInSeconds();
     mHandlerActive = true;
 
@@ -350,8 +331,15 @@ nsHttpHandler::Init()
     // Goanna slice version
     mProductSub.AssignLiteral(MOZILLA_UAVERSION);
     
-    if (mProductSub.IsEmpty())
-        mProductSub.Assign(dynamicBuildID);
+    if (mProductSub.IsEmpty()) {
+      nsCString dynamicBuildID;
+      if (appInfo) {
+        appInfo->GetPlatformBuildID(dynamicBuildID);
+        if (dynamicBuildID.Length() > 8 )
+          dynamicBuildID.Left(dynamicBuildID, 8);
+      }
+      mProductSub.Assign(dynamicBuildID);
+    }
 
 #if DEBUG
     // dump user agent prefs
@@ -657,6 +645,37 @@ nsHttpHandler::GenerateHostPort(const nsCString& host, int32_t port,
 // nsHttpHandler <private>
 //-----------------------------------------------------------------------------
 
+void
+nsHttpHandler::BuildAppVersion()
+{
+    nsCOMPtr<nsIXULAppInfo> appInfo = do_GetService("@mozilla.org/xre/app-info;1");
+
+    nsCString dynamicBuildID;
+    if (appInfo) {
+      appInfo->GetPlatformBuildID(dynamicBuildID);
+      if (dynamicBuildID.Length() > 8 )
+        dynamicBuildID.Left(dynamicBuildID, 8);
+    }
+
+    if (mAppVersionIsBuildID) {
+      // Override BuildID
+      mAppVersion.Assign(dynamicBuildID);
+    } else if (appInfo) {
+      appInfo->GetVersion(mAppVersion);
+    } else {
+      // Fall back to platform if appInfo is unavailable
+      mAppVersion.AssignLiteral(MOZILLA_UAVERSION);
+    }
+
+    // If there's still no version set, set it to a fixed BuildID
+    if (mAppVersion.IsEmpty()) {
+      mAppVersion.AssignLiteral(MOZ_UA_BUILDID);
+    }
+    if (mAppVersion.IsEmpty()) {
+      mAppVersion.AssignLiteral("20200101");
+    }
+}
+
 const nsAFlatCString &
 nsHttpHandler::UserAgent()
 {
@@ -782,21 +801,6 @@ nsHttpHandler::InitUserAgentComponents()
     );
 #endif
 
-
-#ifdef MOZ_MULET
-    {
-        // Add the `Mobile` or `Tablet` or `TV` token when running in the b2g
-        // desktop simulator via preference.
-        nsCString deviceType;
-        nsresult rv = Preferences::GetCString("devtools.useragent.device_type", &deviceType);
-        if (NS_SUCCEEDED(rv)) {
-            mCompatDevice.Assign(deviceType);
-        } else {
-            mCompatDevice.AssignLiteral("Mobile");
-        }
-    }
-#endif // MOZ_MULET
-
 #ifndef MOZ_UA_OS_AGNOSTIC
     // Gather OS/CPU.
 #if defined(XP_WIN)
@@ -924,6 +928,10 @@ nsHttpHandler::PrefsChanged(nsIPrefBranch *prefs, const char *pref)
     if (PREF_CHANGED(UA_PREF("appVersionIsBuildID"))) {
         rv = prefs->GetBoolPref(UA_PREF("appVersionIsBuildID"), &cVar);
         mAppVersionIsBuildID = (NS_SUCCEEDED(rv) && cVar);
+        
+        // Rebuild application version string.
+        BuildAppVersion();
+
         mUserAgentIsDirty = true;
     }
 

netwerk/protocol/http/nsHttpHandler.h

@@ -391,6 +391,7 @@ private:
     //
     // Useragent/prefs helper methods
     //
+    void     BuildAppVersion();
     void     BuildUserAgent();
     void     InitUserAgentComponents();
     void     PrefsChanged(nsIPrefBranch *prefs, const char *pref);