added new option to disable post diffs /cc @BenLubar

public/language/en-GB/admin/settings/post.json

@@ -49,5 +49,6 @@
 	"composer.enable-plugin-help": "Allow plugins to add content to the help tab",
 	"composer.custom-help": "Custom Help Text",
 	"ip-tracking": "IP Tracking",
-	"ip-tracking.each-post": "Track IP Address for each post"
+	"ip-tracking.each-post": "Track IP Address for each post",
+	"enable-post-history": "Enable Post History"
 }

src/controllers/api.js

@@ -61,6 +61,7 @@ apiController.loadConfig = function (req, callback) {
 	config.searchEnabled = plugins.hasListeners('filter:search.query');
 	config.bootswatchSkin = meta.config.bootswatchSkin || 'noskin';
 	config.defaultBootswatchSkin = meta.config.bootswatchSkin || 'noskin';
+	config.enablePostHistory = parseInt(meta.config.enablePostHistory || 1, 10) === 1;
 
 	if (config.useOutgoingLinksPage) {
 		config.outgoingLinksWhitelist = meta.config['outgoingLinks:whitelist'];

src/posts/diffs.js

@@ -5,12 +5,17 @@ var validator = require('validator');
 var diff = require('diff');
 
 var db = require('../database');
+var meta = require('../meta');
 var plugins = require('../plugins');
 var translator = require('../translator');
 
 var Diffs = {};
 
 Diffs.exists = function (pid, callback) {
+	if (parseInt(meta.config.enablePostHistory || 1, 10) !== 1) {
+		return callback(null, 0);
+	}
+
 	db.listLength('post:' + pid + ':diffs', function (err, numDiffs) {
 		return callback(err, !!numDiffs);
 	});

src/posts/edit.js

@@ -5,6 +5,7 @@ var validator = require('validator');
 var _ = require('lodash');
 
 var db = require('../database');
+var meta = require('../meta');
 var topics = require('../topics');
 var user = require('../user');
 var privileges = require('../privileges');
@@ -66,6 +67,10 @@ module.exports = function (Posts) {
 				Posts.setPostFields(data.pid, postData, next);
 			},
 			function (next) {
+				if (parseInt(meta.config.enablePostHistory || 1, 10) !== 1) {
+					return setImmediate(next);
+				}
+
 				Posts.diffs.save(data.pid, oldContent, data.content, next);
 			},
 			function (next) {

src/views/admin/settings/post.tpl

@@ -236,6 +236,12 @@
 				<label for="composer:customHelpText">[[admin/settings/post:composer.custom-help]]</label>
 				<textarea class="form-control" id="composer:customHelpText" data-field="composer:customHelpText" rows="5"></textarea>
 			</div>
+			<div class="checkbox">
+				<label class="mdl-switch mdl-js-switch mdl-js-ripple-effect" for="enablePostHistory">
+					<input class="mdl-switch__input" type="checkbox" id="enablePostHistory" data-field="enablePostHistory" checked />
+					<span class="mdl-switch__label">[[admin/settings/post:enable-post-history]]</span>
+				</label>
+			</div>
 		</form>
 	</div>
 </div>