Fix parsing of true color in ANSI strings.

Author: jonathanslenders

prompt_toolkit/formatted_text/ansi.py

@@ -173,7 +173,7 @@ def _select_graphic_rendition(self, attrs: List[int]) -> None:
                 # True colors.
                 if n == 2 and len(attrs) >= 3:
                     try:
-                        color_str = "%02x%02x%02x" % (
+                        color_str = "#%02x%02x%02x" % (
                             attrs.pop(),
                             attrs.pop(),
                             attrs.pop(),

tests/test_formatted_text.py

@@ -98,6 +98,13 @@ def test_ansi_256_color():
     ]
 
 
+def test_ansi_true_color():
+    assert to_formatted_text(ANSI("\033[38;2;144;238;144m$\033[0;39;49m ")) == [
+        ("#90ee90", "$"),
+        ("ansidefault bg:ansidefault", " "),
+    ]
+
+
 def test_interpolation():
     value = Template(" {} ").format(HTML("<b>hello</b>"))