Fix displaying bright color variation in terminal output (Gallopsled#2373)

* Recompute text.has_bright when num_colors changes

The number of simultaneous colors in the current terminal are queried
later during initialization and the text.num_colors attribute is updated accordingly.
The text.has_bright attribute wasn't updated when that happened and always
remained set to False. Calculate those properties based on num_colors dynamically.

* Update CHANGELOG

* Enable bright colors on Windows too

Only get "colors" on Windows to avoid Gallopsled#1201 again.

* Fix support for old terminals on windows

Author: peace-maker

CHANGELOG.md

@@ -129,6 +129,11 @@ The table below shows which release corresponds to each branch, and what date th
 [2347]: https://github.com/Gallopsled/pwntools/pull/2347
 [2233]: https://github.com/Gallopsled/pwntools/pull/2233
 
+## 4.12.1
+- [#2373][2373] Fix displaying bright color variation in terminal output
+
+[2373]: https://github.com/Gallopsled/pwntools/pull/2373
+
 ## 4.12.0 (`stable`)
 
 - [#2202][2202] Fix `remote` and `listen` in sagemath

pwnlib/term/text.py

@@ -27,9 +27,7 @@ class Module(types.ModuleType):
     def __init__(self):
         self.__file__ = __file__
         self.__name__ = __name__
-        self.num_colors = 8
-        self.has_bright = self.num_colors >= 16
-        self.has_gray = self.has_bright
+        self.num_colors = termcap.get('colors', 8) if sys.platform == 'win32' else 8
         self.when = 'auto'
         self._colors = {
             'black': 0,
@@ -61,6 +59,14 @@ def when(self):
     def when(self, val):
         self._when = eval_when(val)
 
+    @property
+    def has_bright(self):
+        return self.num_colors >= 16
+    
+    @property
+    def has_gray(self):
+        return self.has_bright
+
     def _fg_color(self, c):
         c = termcap.get('setaf', c) or termcap.get('setf', c)
         if not hasattr(c, 'encode'):