From b6173752192682f8156b791e06e7985913621d76 Mon Sep 17 00:00:00 2001
From: Tobias Bieniek <tobias.bieniek@gmail.com>
Date: Thu, 23 Feb 2017 17:44:31 +0100
Subject: [PATCH 1/2] Parser: Change suffix to use ES6 default module export

- This export will be transpiled by Babel for the cjs distribution,
  but will enable others to  use a pure ES6 module distribution
- Instanbul: Ignore "parser.js" for coverage reporting. This file was ignored before
  via annotation, but this has no effect anymore due to the above change
- Remove istanbul annotation from `parser-prefix` (@nknapp)

Squashed by @nknapp

(cherry picked from commit 508347e)
---
 .istanbul.yml        | 2 +-
 src/parser-prefix.js | 2 +-
 src/parser-suffix.js | 3 +--
 3 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/.istanbul.yml b/.istanbul.yml
index e6911f19..960643ef 100644
--- a/.istanbul.yml
+++ b/.istanbul.yml
@@ -1,2 +1,2 @@
 instrumentation:
-    excludes: ['**/spec/**']
+    excludes: ['**/spec/**', '**/handlebars/compiler/parser.js']
diff --git a/src/parser-prefix.js b/src/parser-prefix.js
index e26b9934..d9ed0411 100644
--- a/src/parser-prefix.js
+++ b/src/parser-prefix.js
@@ -1 +1 @@
-/* istanbul ignore next */
+// File ignored in coverage tests via setting in .istanbul.yml
diff --git a/src/parser-suffix.js b/src/parser-suffix.js
index 1f69f7a4..6e4aa20d 100644
--- a/src/parser-suffix.js
+++ b/src/parser-suffix.js
@@ -1,2 +1 @@
-exports.__esModule = true;
-exports['default'] = handlebars;
+export default handlebars;

From c8f4b570c14746c6e9f0c5a39056e5ee4be2f5e1 Mon Sep 17 00:00:00 2001
From: Nils Knappmeier <github@knappi.org>
Date: Thu, 9 Mar 2017 21:17:52 +0100
Subject: [PATCH 2/2] Fix context-stack when calling block-helpers on null
 values

Fixes #1319

Original behaviour:
- When a block-helper was called on a null-context, an empty object was used
  as context instead. (#1093)
- The runtime verifies that whether the current context equals the
  last context and adds the current context to the stack, if it is not.
  This is done, so that inside a block-helper, the ".." path can be used
  to go back to the parent element.
- If the helper is called on a "null" element, the context was added, even
  though it shouldn't be, because the "null != {}"

Fix:
- The commit replaces "null" by the identifiable "container.nullContext"
  instead of "{}". "nullContext" is a sealed empty object.
- An additional check in the runtime verifies that the context is
  only added to the stack, if it is not the nullContext.

Backwards compatibility within 4.0.x-versions:
- This commit changes the compiler and compiled templates would not work
  with runtime-versions 4.0.0 - 4.0.6, because of the "nullContext"
  property. That's way, the compiled code reads
  "(container.nullContext || {})" so that the behavior will degrade
  gracefully with older runtime versions: Everything else will work
  fine, but GH-1319 will still be broken, if you use a newer compiler
  with a pre 4.0.7 runtime.
---
 lib/handlebars/compiler/javascript-compiler.js | 2 +-
 lib/handlebars/runtime.js                      | 4 +++-
 spec/regressions.js                            | 5 +++++
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/lib/handlebars/compiler/javascript-compiler.js b/lib/handlebars/compiler/javascript-compiler.js
index ec891176..bf4be8af 100644
--- a/lib/handlebars/compiler/javascript-compiler.js
+++ b/lib/handlebars/compiler/javascript-compiler.js
@@ -987,7 +987,7 @@ JavaScriptCompiler.prototype = {
     let params = [],
         paramsInit = this.setupHelperArgs(name, paramSize, params, blockHelper);
     let foundHelper = this.nameLookup('helpers', name, 'helper'),
-        callContext = this.aliasable(`${this.contextName(0)} != null ? ${this.contextName(0)} : {}`);
+        callContext = this.aliasable(`${this.contextName(0)} != null ? ${this.contextName(0)} : (container.nullContext || {})`);
 
     return {
       params: params,
diff --git a/lib/handlebars/runtime.js b/lib/handlebars/runtime.js
index 5a79b710..1c084ce3 100644
--- a/lib/handlebars/runtime.js
+++ b/lib/handlebars/runtime.js
@@ -124,6 +124,8 @@ export function template(templateSpec, env) {
 
       return obj;
     },
+    // An empty object to use as replacement for null-contexts
+    nullContext: Object.seal({}),
 
     noop: env.VM.noop,
     compilerInfo: templateSpec.compiler
@@ -187,7 +189,7 @@ export function template(templateSpec, env) {
 export function wrapProgram(container, i, fn, data, declaredBlockParams, blockParams, depths) {
   function prog(context, options = {}) {
     let currentDepths = depths;
-    if (depths && context != depths[0]) {
+    if (depths && context != depths[0] && !(context === container.nullContext && depths[0] === null)) {
       currentDepths = [context].concat(depths);
     }
 
diff --git a/spec/regressions.js b/spec/regressions.js
index 4a2a55cd..6aca9088 100644
--- a/spec/regressions.js
+++ b/spec/regressions.js
@@ -277,4 +277,9 @@ describe('Regressions', function() {
 
     shouldCompileTo(string, { listOne: ['a'], listTwo: ['b']}, 'ab', '');
   });
+
+  it('GH-1319: "unless" breaks when "each" value equals "null"', function() {
+    var string = '{{#each list}}{{#unless ./prop}}parent={{../value}} {{/unless}}{{/each}}';
+    shouldCompileTo(string, { value: 'parent', list: [ null, 'a'] }, 'parent=parent parent=parent ', '');
+  });
 });