Add some guidance on upgrading from v3 to v4

* Prevent deprecation notices for implode, json_encode and substr modifiers.
* unit tests

CHANGELOG.md

@@ -6,9 +6,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+- Using the `|implode`, `|json_encode` and `|substr` modifiers does not generate a deprecation warning anymore as they will continue to be supported in v5 [#939](https://github.com/smarty-php/smarty/issues/939) 
+
 ### Added
 - PHP8.3 support [#925](https://github.com/smarty-php/smarty/issues/925)
 
+### Fixed
+- Incorrect compilation of expressions when escape_html=true [#930](https://github.com/smarty-php/smarty/pull/930)
+
 ## [4.3.4] - 2023-09-14
 
 ## [4.3.3] - 2023-09-14

docs/upgrading.md

@@ -0,0 +1,38 @@
+# Upgrading from an older version
+
+## Upgrading from v3 to v4
+
+Smarty 4 is mostly identical to Smarty 3. Most notably, it adds support for PHP8 and drops support for PHP7.0 and below.
+Additionally, some deprecated features that have long been discouraged have been dropped from the language.
+
+### Muting PHP8 warnings
+If you simultaneously upgrade Smarty to v4 van PHP to v8, you may notice your error logs filling up with warnings about undefined or null template vars
+due to a change in how PHP handles these. This may be helpful to spot errors, but if you find this annoying, you can use
+`$smarty->muteUndefinedOrNullWarnings()` to make Smarty convert these warnings into notices.
+
+### ASP tags
+You can no longer user ASP-style tags like `<% %>` and `<%= %>` in your templates.
+Replace them with `{...}` tags.
+
+### SmartyBC
+Check your codebase for `SmartyBC`.
+We have dropped deprecated API calls that where only accessible through the SmartyBC class.
+
+### No more embedded PHP
+We have completely dropped support for `{php}` and `{include_php}` tags and embedded PHP in templates.
+Check your templates for this, and rewrite any embedded PHP blocks, by moving logic to your PHP files or by
+creating a [plugin function](./programmers/plugins/plugins-functions.md).
+
+### Other changes
+
+Search your code for the following changes:
+
+- `SMARTY_RESOURCE_CHAR_SET` and `SMARTY_RESOURCE_DATE_FORMAT` constants have been removed
+- `Smarty::muteExpectedErrors` and `Smarty::unmuteExpectedErrors` API methods have been removed
+- `Smarty::getVariable` method has been removed. Use [Smarty::getTemplateVars](programmers/api-functions/api-get-template-vars.md) instead.
+- [Smarty::registerResource](programmers/api-functions/api-register-resource.md) no longer accepts an array of callback functions
+
+
+
+
+

libs/plugins/modifier.implode.php

@@ -0,0 +1,15 @@
+<?php
+/**
+ * Smarty plugin
+ *
+ * @package    Smarty
+ * @subpackage PluginsModifier
+ */
+
+function smarty_modifier_implode($values, $separator = '')
+{
+	if (is_array($separator)) {
+		return implode((string) ($values ?? ''), (array) $separator);
+	}
+	return implode((string) ($separator ?? ''), (array) $values);
+}

libs/plugins/modifiercompiler.json_encode.php

@@ -0,0 +1,11 @@
+<?php
+
+/**
+ * Smarty plugin
+ *
+ * @package    Smarty
+ * @subpackage PluginsModifierCompiler
+ */
+function smarty_modifiercompiler_json_encode($params) {
+	return 'json_encode(' . $params[0] . (isset($params[1]) ? ', (int) ' . $params[1] : '') . ')';
+}

libs/plugins/modifiercompiler.substr.php

@@ -0,0 +1,12 @@
+<?php
+
+/**
+ * Smarty plugin
+ *
+ * @package    Smarty
+ * @subpackage PluginsModifierCompiler
+ */
+function smarty_modifiercompiler_substr($params) {
+	return 'substr((string) ' . $params[0] . ', (int) ' . $params[1] .
+		(isset($params[2]) ? ', (int) ' . $params[2] : '') . ')';
+}

libs/sysplugins/smarty_internal_compile_private_print_expression.php

@@ -93,7 +93,7 @@ class Smarty_Internal_Compile_Private_Print_Expression extends Smarty_Internal_C
                 }
                 // autoescape html
                 if ($compiler->template->smarty->escape_html) {
-                    $output = "htmlspecialchars((string) {$output}, ENT_QUOTES, '" . addslashes(Smarty::$_CHARSET) . "')";
+                    $output = "htmlspecialchars((string) ({$output}), ENT_QUOTES, '" . addslashes(Smarty::$_CHARSET) . "')";
                 }
                 // loop over registered filters
                 if (!empty($compiler->template->smarty->registered_filters[ Smarty::FILTER_VARIABLE ])) {

mkdocs.yml

@@ -26,7 +26,9 @@ markdown_extensions:
 
 nav:
   - Home: 'index.md'
-  - 'Getting started': 'getting-started.md'
+  - 'Getting started':
+    - Introduction: 'getting-started.md'
+    - 'Upgrading from an older version': 'upgrading.md'
   - 'Designers':
     - 'Basic Syntax':
         - Introduction: 'designers/language-basic-syntax/index.md'

tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierImplodeTest.php

@@ -0,0 +1,44 @@
+<?php
+/**
+ * Smarty PHPunit tests of modifier
+ */
+
+/**
+ * class for modifier tests
+ *
+ * @runTestsInSeparateProcess
+ * @preserveGlobalState    disabled
+ * @backupStaticAttributes enabled
+ */
+class PluginModifierImplodeTest extends PHPUnit_Smarty
+{
+	public function setUp(): void
+	{
+		$this->setUpSmarty(__DIR__);
+	}
+
+	public function testDefault()
+	{
+		$tpl = $this->smarty->createTemplate('string:{""|implode:$v}');
+		$tpl->assign("v", ["1", "2"]);
+		$this->assertEquals("12", $this->smarty->fetch($tpl));
+	}
+	public function testWithSeparator()
+	{
+		$tpl = $this->smarty->createTemplate('string:{","|implode:$v}');
+		$tpl->assign("v", ["a", "b"]);
+		$this->assertEquals("a,b", $this->smarty->fetch($tpl));
+	}
+	public function testInConditional()
+	{
+		$tpl = $this->smarty->createTemplate('string:{if implode("", $v) == "abc"}good{else}bad{/if}');
+		$tpl->assign("v", ['a','b','c']);
+		$this->assertEquals("good", $this->smarty->fetch($tpl));
+	}
+	public function testInConditionalWithSeparator()
+	{
+		$tpl = $this->smarty->createTemplate('string:{if implode("-", $v) == "a-b-c"}good{else}bad{/if}');
+		$tpl->assign("v", ['a','b','c']);
+		$this->assertEquals("good", $this->smarty->fetch($tpl));
+	}
+}

tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierJsonEncodeTest.php

@@ -0,0 +1,76 @@
+<?php
+/**
+ * Smarty PHPunit tests of modifier
+ */
+
+/**
+ * class for modifier tests
+ *
+ * @runTestsInSeparateProcess
+ * @preserveGlobalState    disabled
+ * @backupStaticAttributes enabled
+ */
+class PluginModifierJsonEncodeTest extends PHPUnit_Smarty
+{
+	public function setUp(): void
+	{
+		$this->setUpSmarty(__DIR__);
+	}
+
+	/**
+	 * @dataProvider dataForDefault
+	 */
+	public function testDefault($value, $expected)
+	{
+		$tpl = $this->smarty->createTemplate('string:{$v|json_encode}');
+		$tpl->assign("v", $value);
+		$this->assertEquals($expected, $this->smarty->fetch($tpl));
+	}
+
+	/**
+	 * @dataProvider dataForDefault
+	 */
+	public function testDefaultAsFunction($value, $expected)
+	{
+		$tpl = $this->smarty->createTemplate('string:{json_encode($v)}');
+		$tpl->assign("v", $value);
+		$this->assertEquals($expected, $this->smarty->fetch($tpl));
+	}
+
+	public function dataForDefault() {
+		return [
+			["abc", '"abc"'],
+			[["abc"], '["abc"]'],
+			[["abc",["a"=>2]], '["abc",{"a":2}]'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataForForceObject
+	 */
+	public function testForceObject($value, $expected)
+	{
+		$tpl = $this->smarty->createTemplate('string:{$v|json_encode:16}');
+		$tpl->assign("v", $value);
+		$this->assertEquals($expected, $this->smarty->fetch($tpl));
+	}
+
+	/**
+	 * @dataProvider dataForForceObject
+	 */
+	public function testForceObjectAsFunction($value, $expected)
+	{
+		$tpl = $this->smarty->createTemplate('string:{json_encode($v,16)}');
+		$tpl->assign("v", $value);
+		$this->assertEquals($expected, $this->smarty->fetch($tpl));
+	}
+
+	public function dataForForceObject() {
+		return [
+			["abc", '"abc"'],
+			[["abc"], '{"0":"abc"}'],
+			[["abc",["a"=>2]], '{"0":"abc","1":{"a":2}}'],
+		];
+	}
+
+}

tests/UnitTests/TemplateSource/TagTests/PluginModifier/PluginModifierSubstrTest.php

@@ -0,0 +1,48 @@
+<?php
+/**
+ * Smarty PHPunit tests of modifier
+ */
+
+/**
+ * class for modifier tests
+ *
+ * @runTestsInSeparateProcess
+ * @preserveGlobalState    disabled
+ * @backupStaticAttributes enabled
+ */
+class PluginModifierSubstrTest extends PHPUnit_Smarty
+{
+	public function setUp(): void
+	{
+		$this->setUpSmarty(__DIR__);
+	}
+
+	public function testDefault()
+	{
+		$tpl = $this->smarty->createTemplate('string:{$v|substr:1}');
+		$tpl->assign("v", "abc");
+		$this->assertEquals("bc", $this->smarty->fetch($tpl));
+	}
+
+	public function testTwoArguments()
+	{
+		$tpl = $this->smarty->createTemplate('string:{$v|substr:1:1}');
+		$tpl->assign("v", "abc");
+		$this->assertEquals("b", $this->smarty->fetch($tpl));
+	}
+
+	public function testNegativeOffset()
+	{
+		$tpl = $this->smarty->createTemplate('string:{$v|substr:-1}');
+		$tpl->assign("v", "abc");
+		$this->assertEquals("c", $this->smarty->fetch($tpl));
+	}
+
+	public function testInConditional()
+	{
+		$tpl = $this->smarty->createTemplate('string:{if substr($v, -1) == "c"}good{else}bad{/if}');
+		$tpl->assign("v", "abc");
+		$this->assertEquals("good", $this->smarty->fetch($tpl));
+	}
+
+}