Use a pref for supported Sync server API levels

3 files changed, 27 insertions, 24 deletions

diff --git a/application/palemoon/branding/shared/pref/preferences.inc b/application/palemoon/branding/shared/pref/preferences.inc
index 51a1852e6..58539aeb2 100644
--- a/application/palemoon/branding/shared/pref/preferences.inc
+++ b/application/palemoon/branding/shared/pref/preferences.inc
@@ -115,6 +115,7 @@ pref("image.mem.decode_bytes_at_a_time", 65536); //larger chunks
 // Sync server URL
 pref("services.sync.serverURL","https://pmsync.palemoon.org/sync/index.php/");
 pref("services.sync.jpake.serverURL","https://keyserver.palemoon.org/");
+pref("services.sync.APILevel", 1); // FSyncMS doesn't support info/configuration
 
 // ============================================================================
 
diff --git a/services/sync/modules/service.js b/services/sync/modules/service.js
index 5b97fcca3..f8c64b0fa 100644
--- a/services/sync/modules/service.js
+++ b/services/sync/modules/service.js
@@ -1067,33 +1067,34 @@ Sync11Service.prototype = {
   // Note: returns false if we failed for a reason other than the server not yet
   // supporting the api.
   _fetchServerConfiguration() {
-#if 0 // FSyncMS doesn't support this and it will break auth if left enabled!
-    // This is similar to _fetchInfo, but with different error handling.
+    if (Svc.Prefs.get("APILevel") >= 2) {
+      // This is similar to _fetchInfo, but with different error handling.
+      // Only supported by later sync implementations.
 
-    let infoURL = this.userBaseURL + "info/configuration";
-    this._log.debug("Fetching server configuration", infoURL);
-    let configResponse;
-    try {
-      configResponse = this.resource(infoURL).get();
-    } catch (ex) {
-      // This is probably a network or similar error.
-      this._log.warn("Failed to fetch info/configuration", ex);
-      this.errorHandler.checkServerError(ex);
-      return false;
-    }
+      let infoURL = this.userBaseURL + "info/configuration";
+      this._log.debug("Fetching server configuration", infoURL);
+      let configResponse;
+      try {
+        configResponse = this.resource(infoURL).get();
+      } catch (ex) {
+        // This is probably a network or similar error.
+        this._log.warn("Failed to fetch info/configuration", ex);
+        this.errorHandler.checkServerError(ex);
+        return false;
+      }
 
-    if (configResponse.status == 404) {
-      // This server doesn't support the URL yet - that's OK.
-      this._log.debug("info/configuration returned 404 - using default upload semantics");
-    } else if (configResponse.status != 200) {
-      this._log.warn(`info/configuration returned ${configResponse.status} - using default configuration`);
-      this.errorHandler.checkServerError(configResponse);
-      return false;
-    } else {
-      this.serverConfiguration = configResponse.obj;
+      if (configResponse.status == 404) {
+        // This server doesn't support the URL yet - that's OK.
+        this._log.debug("info/configuration returned 404 - using default upload semantics");
+      } else if (configResponse.status != 200) {
+        this._log.warn(`info/configuration returned ${configResponse.status} - using default configuration`);
+        this.errorHandler.checkServerError(configResponse);
+        return false;
+      } else {
+        this.serverConfiguration = configResponse.obj;
+      }
+      this._log.trace("info/configuration for this server", this.serverConfiguration);
     }
-    this._log.trace("info/configuration for this server", this.serverConfiguration);
-#endif
     return true;
   },
 
diff --git a/services/sync/services-sync.js b/services/sync/services-sync.js
index f4167c1ce..ebac4412b 100644
--- a/services/sync/services-sync.js
+++ b/services/sync/services-sync.js
@@ -12,6 +12,7 @@ pref("services.sync.syncKeyHelpURL", "https://services.mozilla.com/help/synckey"
 
 pref("services.sync.lastversion", "firstrun");
 pref("services.sync.sendVersionInfo", true);
+pref("services.sync.APILevel", 2);
 
 pref("services.sync.scheduler.eolInterval",         604800); // 1 week
 pref("services.sync.scheduler.idleInterval",         3600);  // 1 hour