feat: Run setter logic for nested setters even if value didn't change

Run setter logic for nested setters even if value didn't change. See this:
vuejs#7828 (comment).

BREAKING CHANGE: Run setter logic for nested setters even if value didn't change.

Author: jan-swiecki

dist/vue.common.dev.js

@@ -973,7 +973,7 @@ class Observer {
   walk (obj) {
     const keys = Object.keys(obj);
     for (let i = 0; i < keys.length; i++) {
-      defineReactive$$1(obj, keys[i]);
+      defineReactive(obj, keys[i]);
     }
   }
 
@@ -1041,7 +1041,7 @@ function observe (value, asRootData) {
 /**
  * Define a reactive property on an Object.
  */
-function defineReactive$$1 (
+function defineReactive (
   obj,
   key,
   val,
@@ -1082,7 +1082,9 @@ function defineReactive$$1 (
     set: function reactiveSetter (newVal) {
       const value = getter ? getter.call(obj) : val;
       /* eslint-disable no-self-compare */
-      if (newVal === value || (newVal !== newVal && value !== value)) {
+      // We allow same values for getters
+      // See this: https://github.com/vuejs/vue/pull/7828#issuecomment-446820288
+      if ((newVal === value && !getter) || (newVal !== newVal && value !== value)) {
         return
       }
       /* eslint-enable no-self-compare */
@@ -1133,7 +1135,7 @@ function set (target, key, val) {
     target[key] = val;
     return val
   }
-  defineReactive$$1(ob.value, key, val);
+  defineReactive(ob.value, key, val);
   ob.dep.notify();
   return val
 }
@@ -1526,9 +1528,9 @@ function normalizeDirectives (options) {
   const dirs = options.directives;
   if (dirs) {
     for (const key in dirs) {
-      const def$$1 = dirs[key];
-      if (typeof def$$1 === 'function') {
-        dirs[key] = { bind: def$$1, update: def$$1 };
+      const def = dirs[key];
+      if (typeof def === 'function') {
+        dirs[key] = { bind: def, update: def };
       }
     }
   }
@@ -2187,13 +2189,13 @@ function _traverse (val, seen) {
 const normalizeEvent = cached((name) => {
   const passive = name.charAt(0) === '&';
   name = passive ? name.slice(1) : name;
-  const once$$1 = name.charAt(0) === '~'; // Prefixed last, checked first
-  name = once$$1 ? name.slice(1) : name;
+  const once = name.charAt(0) === '~'; // Prefixed last, checked first
+  name = once ? name.slice(1) : name;
   const capture = name.charAt(0) === '!';
   name = capture ? name.slice(1) : name;
   return {
     name,
-    once: once$$1,
+    once,
     capture,
     passive
   }
@@ -2220,13 +2222,13 @@ function updateListeners (
   on,
   oldOn,
   add,
-  remove$$1,
+  remove,
   createOnceHandler,
   vm
 ) {
-  let name, def$$1, cur, old, event;
+  let name, def, cur, old, event;
   for (name in on) {
-    def$$1 = cur = on[name];
+    def = cur = on[name];
     old = oldOn[name];
     event = normalizeEvent(name);
     if (isUndef(cur)) {
@@ -2250,7 +2252,7 @@ function updateListeners (
   for (name in oldOn) {
     if (isUndef(on[name])) {
       event = normalizeEvent(name);
-      remove$$1(event.name, oldOn[name], event.capture);
+      remove(event.name, oldOn[name], event.capture);
     }
   }
 }
@@ -2462,7 +2464,7 @@ function initInjections (vm) {
     Object.keys(result).forEach(key => {
       /* istanbul ignore else */
       {
-        defineReactive$$1(vm, key, result[key], () => {
+        defineReactive(vm, key, result[key], () => {
           warn(
             `Avoid mutating an injected value directly since the changes will be ` +
             `overwritten whenever the provided component re-renders. ` +
@@ -3511,10 +3513,10 @@ function initRender (vm) {
 
   /* istanbul ignore else */
   {
-    defineReactive$$1(vm, '$attrs', parentData && parentData.attrs || emptyObject, () => {
+    defineReactive(vm, '$attrs', parentData && parentData.attrs || emptyObject, () => {
       !isUpdatingChildComponent && warn(`$attrs is readonly.`, vm);
     }, true);
-    defineReactive$$1(vm, '$listeners', options._parentListeners || emptyObject, () => {
+    defineReactive(vm, '$listeners', options._parentListeners || emptyObject, () => {
       !isUpdatingChildComponent && warn(`$listeners is readonly.`, vm);
     }, true);
   }
@@ -4391,7 +4393,7 @@ function queueWatcher (watcher) {
 
 
 
-let uid$2 = 0;
+let uid$1 = 0;
 
 /**
  * A watcher parses an expression, collects dependencies,
@@ -4440,7 +4442,7 @@ class Watcher {
       this.deep = this.user = this.lazy = this.sync = false;
     }
     this.cb = cb;
-    this.id = ++uid$2; // uid for batching
+    this.id = ++uid$1; // uid for batching
     this.active = true;
     this.dirty = this.lazy; // for lazy watchers
     this.deps = [];
@@ -4674,7 +4676,7 @@ function initProps (vm, propsOptions) {
           vm
         );
       }
-      defineReactive$$1(props, key, value, () => {
+      defineReactive(props, key, value, () => {
         if (!isRoot && !isUpdatingChildComponent) {
           warn(
             `Avoid mutating a prop directly since the value will be ` +
@@ -4955,13 +4957,13 @@ function stateMixin (Vue) {
 
 /*  */
 
-let uid$3 = 0;
+let uid$2 = 0;
 
 function initMixin (Vue) {
   Vue.prototype._init = function (options) {
     const vm = this;
     // a uid
-    vm._uid = uid$3++;
+    vm._uid = uid$2++;
 
     let startTag, endTag;
     /* istanbul ignore if */
@@ -5278,9 +5280,9 @@ function pruneCacheEntry (
   keys,
   current
 ) {
-  const cached$$1 = cache[key];
-  if (cached$$1 && (!current || cached$$1.tag !== current.tag)) {
-    cached$$1.componentInstance.$destroy();
+  const cached = cache[key];
+  if (cached && (!current || cached.tag !== current.tag)) {
+    cached.componentInstance.$destroy();
   }
   cache[key] = null;
   remove(keys, key);
@@ -5387,7 +5389,7 @@ function initGlobalAPI (Vue) {
     warn,
     extend,
     mergeOptions,
-    defineReactive: defineReactive$$1
+    defineReactive
   };
 
   Vue.set = set;
@@ -5854,13 +5856,13 @@ function createPatchFunction (backend) {
   }
 
   function createRmCb (childElm, listeners) {
-    function remove$$1 () {
-      if (--remove$$1.listeners === 0) {
+    function remove () {
+      if (--remove.listeners === 0) {
         removeNode(childElm);
       }
     }
-    remove$$1.listeners = listeners;
-    return remove$$1
+    remove.listeners = listeners;
+    return remove
   }
 
   function removeNode (el) {
@@ -5871,7 +5873,7 @@ function createPatchFunction (backend) {
     }
   }
 
-  function isUnknownElement$$1 (vnode, inVPre) {
+  function isUnknownElement (vnode, inVPre) {
     return (
       !inVPre &&
       !vnode.ns &&
@@ -5920,7 +5922,7 @@ function createPatchFunction (backend) {
         if (data && data.pre) {
           creatingElmInVPre++;
         }
-        if (isUnknownElement$$1(vnode, creatingElmInVPre)) {
+        if (isUnknownElement(vnode, creatingElmInVPre)) {
           warn(
             'Unknown custom element: <' + tag + '> - did you ' +
             'register the component correctly? For recursive components, ' +
@@ -6018,11 +6020,11 @@ function createPatchFunction (backend) {
     insert(parentElm, vnode.elm, refElm);
   }
 
-  function insert (parent, elm, ref$$1) {
+  function insert (parent, elm, ref) {
     if (isDef(parent)) {
-      if (isDef(ref$$1)) {
-        if (nodeOps.parentNode(ref$$1) === parent) {
-          nodeOps.insertBefore(parent, elm, ref$$1);
+      if (isDef(ref)) {
+        if (nodeOps.parentNode(ref) === parent) {
+          nodeOps.insertBefore(parent, elm, ref);
         }
       } else {
         nodeOps.appendChild(parent, elm);
@@ -6436,7 +6438,7 @@ function createPatchFunction (backend) {
   function assertNodeMatch (node, vnode, inVPre) {
     if (isDef(vnode.tag)) {
       return vnode.tag.indexOf('vue-component') === 0 || (
-        !isUnknownElement$$1(vnode, inVPre) &&
+        !isUnknownElement(vnode, inVPre) &&
         vnode.tag.toLowerCase() === (node.tagName && node.tagName.toLowerCase())
       )
     } else {
@@ -7909,20 +7911,20 @@ function removeClass (el, cls) {
 
 /*  */
 
-function resolveTransition (def$$1) {
-  if (!def$$1) {
+function resolveTransition (def) {
+  if (!def) {
     return
   }
   /* istanbul ignore else */
-  if (typeof def$$1 === 'object') {
+  if (typeof def === 'object') {
     const res = {};
-    if (def$$1.css !== false) {
-      extend(res, autoCssTransition(def$$1.name || 'v'));
+    if (def.css !== false) {
+      extend(res, autoCssTransition(def.name || 'v'));
     }
-    extend(res, def$$1);
+    extend(res, def);
     return res
-  } else if (typeof def$$1 === 'string') {
-    return autoCssTransition(def$$1)
+  } else if (typeof def === 'string') {
+    return autoCssTransition(def)
   }
 }
 
@@ -8583,10 +8585,10 @@ function locateNode (vnode) {
 var show = {
   bind (el, { value }, vnode) {
     vnode = locateNode(vnode);
-    const transition$$1 = vnode.data && vnode.data.transition;
+    const transition = vnode.data && vnode.data.transition;
     const originalDisplay = el.__vOriginalDisplay =
       el.style.display === 'none' ? '' : el.style.display;
-    if (value && transition$$1) {
+    if (value && transition) {
       vnode.data.show = true;
       enter(vnode, () => {
         el.style.display = originalDisplay;
@@ -8600,8 +8602,8 @@ var show = {
     /* istanbul ignore if */
     if (!value === !oldValue) return
     vnode = locateNode(vnode);
-    const transition$$1 = vnode.data && vnode.data.transition;
-    if (transition$$1) {
+    const transition = vnode.data && vnode.data.transition;
+    if (transition) {
       vnode.data.show = true;
       if (value) {
         enter(vnode, () => {
@@ -9261,8 +9263,8 @@ function decodeAttr (value, shouldDecodeNewlines) {
 function parseHTML (html, options) {
   const stack = [];
   const expectHTML = options.expectHTML;
-  const isUnaryTag$$1 = options.isUnaryTag || no;
-  const canBeLeftOpenTag$$1 = options.canBeLeftOpenTag || no;
+  const isUnaryTag = options.isUnaryTag || no;
+  const canBeLeftOpenTag = options.canBeLeftOpenTag || no;
   let index = 0;
   let last, lastTag;
   while (html) {
@@ -9424,12 +9426,12 @@ function parseHTML (html, options) {
       if (lastTag === 'p' && isNonPhrasingTag(tagName)) {
         parseEndTag(lastTag);
       }
-      if (canBeLeftOpenTag$$1(tagName) && lastTag === tagName) {
+      if (canBeLeftOpenTag(tagName) && lastTag === tagName) {
         parseEndTag(tagName);
       }
     }
 
-    const unary = isUnaryTag$$1(tagName) || !!unarySlash;
+    const unary = isUnaryTag(tagName) || !!unarySlash;
 
     const l = match.attrs.length;
     const attrs = new Array(l);
@@ -10072,8 +10074,8 @@ function addIfCondition (el, condition) {
 }
 
 function processOnce (el) {
-  const once$$1 = getAndRemoveAttr(el, 'v-once');
-  if (once$$1 != null) {
+  const once = getAndRemoveAttr(el, 'v-once');
+  if (once != null) {
     el.once = true;
   }
 }
@@ -11434,15 +11436,15 @@ function genSlot (el, state) {
         dynamic: attr.dynamic
       })))
     : null;
-  const bind$$1 = el.attrsMap['v-bind'];
-  if ((attrs || bind$$1) && !children) {
+  const bind = el.attrsMap['v-bind'];
+  if ((attrs || bind) && !children) {
     res += `,null`;
   }
   if (attrs) {
     res += `,${attrs}`;
   }
-  if (bind$$1) {
-    res += `${attrs ? '' : ',null'},${bind$$1}`;
+  if (bind) {
+    res += `${attrs ? '' : ',null'},${bind}`;
   }
   return res + ')'
 }
@@ -11671,7 +11673,7 @@ function createCompileToFunctionFn (compile) {
     vm
   ) {
     options = extend({}, options);
-    const warn$$1 = options.warn || warn;
+    const warn$1 = options.warn || warn;
     delete options.warn;
 
     /* istanbul ignore if */
@@ -11681,7 +11683,7 @@ function createCompileToFunctionFn (compile) {
         new Function('return 1');
       } catch (e) {
         if (e.toString().match(/unsafe-eval|CSP/)) {
-          warn$$1(
+          warn$1(
             'It seems you are using the standalone build of Vue.js in an ' +
             'environment with Content Security Policy that prohibits unsafe-eval. ' +
             'The template compiler cannot work in this environment. Consider ' +
@@ -11708,14 +11710,14 @@ function createCompileToFunctionFn (compile) {
       if (compiled.errors && compiled.errors.length) {
         if (options.outputSourceRange) {
           compiled.errors.forEach(e => {
-            warn$$1(
+            warn$1(
               `Error compiling template:\n\n${e.msg}\n\n` +
               generateCodeFrame(template, e.start, e.end),
               vm
             );
           });
         } else {
-          warn$$1(
+          warn$1(
             `Error compiling template:\n\n${template}\n\n` +
             compiled.errors.map(e => `- ${e}`).join('\n') + '\n',
             vm
@@ -11745,7 +11747,7 @@ function createCompileToFunctionFn (compile) {
     /* istanbul ignore if */
     {
       if ((!compiled.errors || !compiled.errors.length) && fnGenErrors.length) {
-        warn$$1(
+        warn$1(
           `Failed to generate render function:\n\n` +
           fnGenErrors.map(({ err, code }) => `${err.toString()} in\n\n${code}\n`).join('\n'),
           vm