Merge pull request #36 from bem-site/BEMINFO-1346

Left links overriding only for blocks of added or changed library versions

src/tasks/override-links.js

@@ -328,7 +328,33 @@ module.exports = function (target) {
         return vow.resolve(target);
     }
 
-    var languages = utility.getLanguages();
+    var languages = utility.getLanguages(),
+        librariesChanges = target.getChanges().getLibraries(),
+        changedLibVersions = []
+            .concat(librariesChanges.getAdded())
+            .concat(librariesChanges.getModified());
+
+    /**
+     * Decides that given nodeValue is needed for override links
+     * @param {Object} nodeValue
+     * @returns {boolean} flag which indicates that it is important to rescan given source
+     * and override or re-override links in it
+     */
+    function isNeedToOverride(nodeValue) {
+        var route = nodeValue.route,
+            conditions,
+            lib,
+            version;
+
+        conditions = route.conditions;
+        lib = conditions.lib;
+        version = conditions.version;
+
+        return changedLibVersions.some(function (item) {
+            return item.lib === lib && item.version === version;
+        });
+    }
+
     return vow.all([
             levelDb.get().getByKeyRange(target.KEY.NODE_PREFIX, target.KEY.PEOPLE_PREFIX),
             collectUrls(target)
@@ -338,6 +364,10 @@ module.exports = function (target) {
                 var nodeValue = nodeRecord.value;
 
                 if (nodeValue.source && nodeValue.source.data) {
+                    if(!isNeedToOverride(nodeValue)) {
+                        return vow.resolve();
+                    }
+
                     return levelDb.get().get(nodeValue.source.data).then(function (blockValue) {
                         if (!blockValue) {
                             return vow.resolve();