fix infinite loop in append

Author: willmcgugan

CHANGELOG.md

@@ -5,6 +5,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Fixed
+
+- Fixed infinite loop when appending Text to same instance
 
 ## [13.8.0] - 2024-08-26
 

rich/text.py

@@ -998,7 +998,7 @@ def append(
  self._text.append(text.plain)
  self._spans.extend(
  _Span(start + text_length, end + text_length, style)
- for start, end, style in text._spans
+ for start, end, style in text._spans.copy()
  )
  self._length += len(text)
  return self
@@ -1020,7 +1020,7 @@ def append_text(self, text: "Text") -> "Text":
  self._text.append(text.plain)
  self._spans.extend(
  _Span(start + text_length, end + text_length, style)
- for start, end, style in text._spans
+ for start, end, style in text._spans.copy()
  )
  self._length += len(text)
  return self

tests/test_text.py

@@ -1001,3 +1001,14 @@ def test_append_tokens() -> None:
  output = capture.get()
  print(repr(output))
  assert output == "long text that will be wrapped with a \ncontrol code \n\n"
+
+
+def test_append_loop_regression() -> None:
+ """Regression text for https://github.com/Textualize/rich/issues/3479"""
+ a = Text("one", "blue")
+ a.append(a)
+ assert a.plain == "oneone"
+
+ b = Text("two", "blue")
+ b.append_text(b)
+ assert b.plain == "twotwo"