Fix non-contiguous program indices

lib/handlebars/compiler/javascript-compiler.js

@@ -164,12 +164,10 @@ JavaScriptCompiler.prototype = {
 
       let { programs, decorators } = this.context;
       for (i = 0, l = programs.length; i < l; i++) {
-        if (programs[i]) {
-          ret[i] = programs[i];
-          if (decorators[i]) {
-            ret[i + '_d'] = decorators[i];
-            ret.useDecorators = true;
-          }
+        ret[i] = programs[i];
+        if (decorators[i]) {
+          ret[i + '_d'] = decorators[i];
+          ret.useDecorators = true;
         }
       }
 
@@ -836,8 +834,8 @@ JavaScriptCompiler.prototype = {
       let existing = this.matchExistingProgram(child);
 
       if (existing == null) {
-        this.context.programs.push(''); // Placeholder to prevent name conflicts for nested children
-        let index = this.context.programs.length;
+        // Placeholder to prevent name conflicts for nested children
+        let index = this.context.programs.push('') - 1;
         child.index = index;
         child.name = 'program' + index;
         this.context.programs[index] = compiler.compile(

spec/expected/non.empty.amd.known.helper.js

@@ -1,6 +1,6 @@
 define(['handlebars.runtime'], function(Handlebars) {
 Handlebars = Handlebars["default"]; var template = Handlebars.template, templates = Handlebars.templates = Handlebars.templates || {};
-return templates['known.helpers'] = template({"1":function(container,depth0,helpers,partials,data) {
+return templates['known.helpers'] = template({"0":function(container,depth0,helpers,partials,data) {
 var stack1, lookupProperty = container.lookupProperty || function(parent, propertyName) {
 if (Object.prototype.hasOwnProperty.call(parent, propertyName)) {
 return parent[propertyName];
@@ -8,8 +8,8 @@ return parent[propertyName];
 return undefined
 };
 return " <div>Some known helper</div>\n" 
-+ ((stack1 = lookupProperty(helpers,"anotherHelper").call(depth0 != null ? depth0 : (container.nullContext || {}),true,{"name":"anotherHelper","hash":{},"fn":container.program(2, data, 0),"inverse":container.noop,"data":data,"loc":{"start":{"line":3,"column":4},"end":{"line":5,"column":22}}})) != null ? stack1 : "");
-},"2":function(container,depth0,helpers,partials,data) {
++ ((stack1 = lookupProperty(helpers,"anotherHelper").call(depth0 != null ? depth0 : (container.nullContext || {}),true,{"name":"anotherHelper","hash":{},"fn":container.program(1, data, 0),"inverse":container.noop,"data":data,"loc":{"start":{"line":3,"column":4},"end":{"line":5,"column":22}}})) != null ? stack1 : "");
+},"1":function(container,depth0,helpers,partials,data) {
 return " <div>Another known helper</div>\n";
 },"compiler":[8,">= 4.3.0"],"main":function(container,depth0,helpers,partials,data) {
 var stack1, lookupProperty = container.lookupProperty || function(parent, propertyName) {
@@ -18,7 +18,7 @@ return parent[propertyName];
 }
 return undefined
 };
-return ((stack1 = lookupProperty(helpers,"someHelper").call(depth0 != null ? depth0 : (container.nullContext || {}),true,{"name":"someHelper","hash":{},"fn":container.program(1, data, 0),"inverse":container.noop,"data":data,"loc":{"start":{"line":1,"column":0},"end":{"line":6,"column":15}}})) != null ? stack1 : "");
+return ((stack1 = lookupProperty(helpers,"someHelper").call(depth0 != null ? depth0 : (container.nullContext || {}),true,{"name":"someHelper","hash":{},"fn":container.program(0, data, 0),"inverse":container.noop,"data":data,"loc":{"start":{"line":1,"column":0},"end":{"line":6,"column":15}}})) != null ? stack1 : "");
 },"useData":true});
 });