chore(release): prepare v6.1.0

Bump Version to 6.1.0 and add CHANGELOG.md covering the release.
6.1.0 is primarily a security update: it closes a {% filter %}
sandbox bypass, fixes two renderer panics reachable from template
input (removetags, {% ifchanged %}), and clarifies that pongo2's
ban-list and loader APIs do not provide a true sandbox.

Author: flosch

CHANGELOG.md

@@ -0,0 +1,62 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+## [6.1.0] - 2026-05-02
+
+This release is primarily a **security and bug-fix update**. All users are
+encouraged to update.
+
+### Fixed
+
+- **`removetags` filter**: tag names containing regex metacharacters no longer
+  panic the renderer.
+- **`{% cycle %}` tag**: cycle index is now tracked per template execution
+  instead of mutated on the parsed AST node. Concurrent renders of a cached
+  template no longer race, and sequential renders no longer leak state from
+  a previous execution.
+- **`{% ifchanged %}` tag**: `lastValues`/`lastContent` are now tracked per
+  template execution instead of mutated on the parsed AST node, fixing both
+  a data race under concurrent renders and state leaking between sequential
+  renders of a cached template.
+- **`{% ifchanged %}` tag**: rendering an `{% ifchanged %}` block without
+  an `{% else %}` branch no longer crashes with a nil-pointer dereference
+  when the watched value is unchanged. Matches Django's behavior of
+  producing no output.
+- **`{% filter %}` tag**: `BanFilter` is now enforced inside `{% filter %}`
+  blocks.
+
+### Changed
+
+- **`{% ssi %}` plaintext mode** now reads the included file through the
+  configured `TemplateLoader` chain instead of `ioutil.ReadFile`, so
+  non-filesystem loaders (`FSLoader`, `HttpFilesystemLoader`, custom)
+  can serve SSI content.
+- **Template error reporting** (`RawLine`) now reads source lines through
+  the template's loader chain instead of opening files directly with
+  `os.Open`. Error line extraction now works for any `TemplateLoader`.
+
+### Removed
+
+- **`SandboxedFilesystemLoader` and `NewSandboxedFilesystemLoader`** have
+  been removed. They were marked WIP, never wired into any enforcement
+  path, and behaved as a thin pass-through to `LocalFilesystemLoader`.
+  Callers should use `LocalFilesystemLoader` directly; sandboxing should
+  be implemented via a custom `TemplateLoader`.
+
+  Note: this is technically an API-breaking removal, but the type was
+  unused WIP code that never provided sandboxing.
+
+### Documentation
+
+- Clarified that pongo2 does **not** provide a true sandbox. `BanTag` and
+  `BanFilter` only refuse to compile templates that reference banned
+  names; they do not isolate Go execution, restrict filesystem access,
+  or contain malicious templates. README, `TemplateSet` field comment,
+  `DefaultLoader` comment, and parser error messages updated accordingly.
+- Added a Security section to the README documenting that template
+  loaders (`LocalFilesystemLoader`, `HttpFilesystemLoader`, `FSLoader`)
+  do not clamp paths to a base directory and that template filenames
+  must be treated as trusted input.
+
+[6.1.0]: https://github.com/flosch/pongo2/compare/v6.0.0...v6.1.0

pongo2.go

@@ -1,7 +1,7 @@
 package pongo2
 
 // Version string
-const Version = "6.0.0"
+const Version = "6.1.0"
 
 // Must panics, if a Template couldn't successfully parsed. This is how you
 // would use it:

template_tests/pongo2ctx.tpl.out

@@ -1 +1 @@
-6.0.0
+6.1.0