bpo-42681: Fix range checks for color and pair numbers in curses (GH-23874)
diff --git a/Doc/library/curses.rst b/Doc/library/curses.rst
index 3684d54..26121ac 100644
--- a/Doc/library/curses.rst
+++ b/Doc/library/curses.rst
@@ -112,14 +112,15 @@
.. function:: color_content(color_number)
Return the intensity of the red, green, and blue (RGB) components in the color
- *color_number*, which must be between ``0`` and :const:`COLORS`. Return a 3-tuple,
+ *color_number*, which must be between ``0`` and ``COLORS - 1``. Return a 3-tuple,
containing the R,G,B values for the given color, which will be between
``0`` (no component) and ``1000`` (maximum amount of component).
-.. function:: color_pair(color_number)
+.. function:: color_pair(pair_number)
- Return the attribute value for displaying text in the specified color. This
+ Return the attribute value for displaying text in the specified color pair.
+ Only the first 256 color pairs are supported. This
attribute value can be combined with :const:`A_STANDOUT`, :const:`A_REVERSE`,
and the other :const:`A_\*` attributes. :func:`pair_number` is the counterpart
to this function.
@@ -287,7 +288,7 @@
Change the definition of a color, taking the number of the color to be changed
followed by three RGB values (for the amounts of red, green, and blue
components). The value of *color_number* must be between ``0`` and
- :const:`COLORS`. Each of *r*, *g*, *b*, must be a value between ``0`` and
+ `COLORS - 1`. Each of *r*, *g*, *b*, must be a value between ``0`` and
``1000``. When :func:`init_color` is used, all occurrences of that color on the
screen immediately change to the new definition. This function is a no-op on
most terminals; it is active only if :func:`can_change_color` returns ``True``.
@@ -300,7 +301,8 @@
color number. The value of *pair_number* must be between ``1`` and
``COLOR_PAIRS - 1`` (the ``0`` color pair is wired to white on black and cannot
be changed). The value of *fg* and *bg* arguments must be between ``0`` and
- :const:`COLORS`. If the color-pair was previously initialized, the screen is
+ ``COLORS - 1``, or, after calling :func:`use_default_colors`, ``-1``.
+ If the color-pair was previously initialized, the screen is
refreshed and all occurrences of that color-pair are changed to the new
definition.
@@ -450,7 +452,7 @@
.. function:: pair_content(pair_number)
Return a tuple ``(fg, bg)`` containing the colors for the requested color pair.
- The value of *pair_number* must be between ``1`` and ``COLOR_PAIRS - 1``.
+ The value of *pair_number* must be between ``0`` and ``COLOR_PAIRS - 1``.
.. function:: pair_number(attr)