Fix subform repeat counter. (#19693)

* Fix subform repeat counter.

As normal rows should be zero indexed.

When length === count === 0, first row should be 0.

Note: PHP creates existing rows with zero index - so if min=1, you
currently get row 0 on form load then row 2, 3 etc. as you add them.

* Update unit tests

* Additional test fixes.

* Fix typo in comment.

* Reminify subform-repeatable.js

media/system/js/subform-repeatable-uncompressed.js

@@ -8,7 +8,7 @@
 	$.subformRepeatable = function(container, options){
 		this.$container = $(container);
 
-		// check if alredy exist
+		// check if already exist
 		if(this.$container.data("subformRepeatable")){
 			return self;
 		}
@@ -144,14 +144,13 @@
 
 	// fix names ind id`s for field that in $row
 	$.subformRepeatable.prototype.fixUniqueAttributes = function($row, count){
-		this.lastRowNum++;
 		var group = $row.attr('data-group'),// current group name
 			basename = $row.attr('data-base-name'), // group base name, without count
 			count    = count || 0,
-			countnew = Math.max(this.lastRowNum, count + 1),
-    		groupnew = basename + countnew; // new group name
+			countnew = Math.max(this.lastRowNum, count),
+			groupnew = basename + countnew; // new group name
 
-		this.lastRowNum = countnew;
+		this.lastRowNum = countnew + 1;
 		$row.attr('data-group', groupnew);
 
 		// Fix inputs that have a "name" attribute

tests/javascript/subform-repeatable/spec.js

@@ -39,26 +39,26 @@ define(['jquery', 'testsRoot/subform-repeatable/spec-setup', 'jasmineJquery'], f
 				expect($container.find('tbody').children().length).toEqual(2);
 			});
 
-			it('Should fix the id of the template input checkbox element to "jform_group__group2__checkbox"', function () {
+			it('Should fix the id of the template input checkbox element to "jform_group__group1__checkbox"', function () {
 				expect($container.find('#jform_group__groupX__checkbox')).not.toExist();
-				expect($container.find('#jform_group__group2__checkbox')).toExist();
+				expect($container.find('#jform_group__group1__checkbox')).toExist();
 			});
 
 			it('Should fix the for attribute of the checkbox label element to match the changed input id', function () {
-				expect($container.find('label[for="jform_group__group2__checkbox"]')).toExist();
+				expect($container.find('label[for="jform_group__group1__checkbox"]')).toExist();
 			});
 
-			it('Should fix the name of the template input checkbox element to "jform[group][group2][checkbox]"', function () {
-				expect($container.find('#jform_group__group2__checkbox')).toHaveAttr('name','jform[group][group2][checkbox]');
+			it('Should fix the name of the template input checkbox element to "jform[group][group1][checkbox]"', function () {
+				expect($container.find('#jform_group__group1__checkbox')).toHaveAttr('name','jform[group][group1][checkbox]');
 			});
 
-			it('Should fix the id of the template input radio element to "jform_group__group2__radio0"', function () {
+			it('Should fix the id of the template input radio element to "jform_group__group1__radio0"', function () {
 				expect($container.find('#jform_group__groupX__radio0')).not.toExist();
-				expect($container.find('#jform_group__group2__radio0')).toExist();
+				expect($container.find('#jform_group__group1__radio0')).toExist();
 			});
 
-			it('Should fix the name of the template input radio element to "jform[group][group2][radio]"', function () {
-				expect($container.find('#jform_group__group2__radio0')).toHaveAttr('name','jform[group][group2][radio]');
+			it('Should fix the name of the template input radio element to "jform[group][group1][radio]"', function () {
+				expect($container.find('#jform_group__group1__radio0')).toHaveAttr('name','jform[group][group1][radio]');
 			});
 
 			it('Should have captured the template correctly', function () {
@@ -76,8 +76,8 @@ define(['jquery', 'testsRoot/subform-repeatable/spec-setup', 'jasmineJquery'], f
 				expect($container.find('tbody').children().last()).toHaveAttr('data-new', 'true');
 			});
 
-			it('Should set data-group attribute to "group2" in the new element', function () {
-				expect($container.find('tbody').children().last()).toHaveAttr('data-group', 'group2');
+			it('Should set data-group attribute to "group1" in the new element', function () {
+				expect($container.find('tbody').children().last()).toHaveAttr('data-group', 'group1');
 			});
 
 			it('Should trigger subform-row-add event', function () {