add note to 'other changes' in upgrade instructions

Fixes #935

changelog/935.md

@@ -0,0 +1 @@
+- Add template path to CompilerException to enable rich debug features [#935](https://github.com/smarty-php/smarty/issues/935)

docs/upgrading.md

@@ -117,6 +117,7 @@ The following constants have been removed to prevent global side effects.
 - Smarty now always runs in multibyte mode. Make sure you use the [PHP multibyte extension](https://www.php.net/manual/en/book.mbstring.php) in production for optimal performance.
 - Generated `<script>` tags lo longer have deprecated `type="text/javascript"` or `language="Javascript"` attributes
 - Smarty will throw a compiler exception instead of silently ignoring a modifier on a function call, like this: `{include|dot:"x-template-id" file="included.dot.tpl"}`
+- The ::getFile() method of a CompilerException will now return the full path of the template being compiled, if possible. This used to be 'file:relative_dir/filename.tpl'.
 
 ## Upgrading from v3 to v4
 

src/Compiler/CodeFrame.php

@@ -121,6 +121,6 @@ class CodeFrame
 	 * @return string
 	 */
 	public function insertLocalVariables(): string {
-		return '$_smarty_current_dir = ' . var_export(dirname($this->_template->getSource()->getFilepath()), true) . ";\n";
+		return '$_smarty_current_dir = ' . var_export(dirname($this->_template->getSource()->getFilepath() ?? '.'), true) . ";\n";
 	}
 }

src/Compiler/Template.php

@@ -848,7 +848,7 @@ class Template extends BaseCompiler {
 		$e = new CompilerException(
 			$error_text,
 			0,
-			$this->template->getSource()->getFullResourceName(),
+			$this->template->getSource()->getFilepath() ?? $this->template->getSource()->getFullResourceName(),
 			$line
 		);
 		$e->source = trim(preg_replace('![\t\r\n]+!', ' ', $match[$line - 1]));

src/Template/Source.php

@@ -271,11 +271,11 @@ class Source {
 		return $this->type . ':' . $this->name;
 	}
 
-	public function getFilepath(): string {
+	public function getFilepath(): ?string {
 		if ($this->handler instanceof FilePlugin) {
 			return $this->handler->getFilePath($this->name, $this->smarty, $this->isConfig);
 		}
-		return '.';
+		return null;
 	}
 
 	public function isConfig(): bool {