Backport PR matplotlib#31898: fix: allow array-like fill_between where masks

Author: cyphercodes

lib/matplotlib/axes/_axes.pyi

@@ -479,7 +479,7 @@ class Axes(_AxesBase):
         x: ArrayLike,
         y1: ArrayLike | float,
         y2: ArrayLike | float = ...,
-        where: Sequence[bool] | None = ...,
+        where: ArrayLike | None = ...,
         interpolate: bool = ...,
         step: Literal["pre", "post", "mid"] | None = ...,
         *,
@@ -491,7 +491,7 @@ class Axes(_AxesBase):
         y: ArrayLike,
         x1: ArrayLike | float,
         x2: ArrayLike | float = ...,
-        where: Sequence[bool] | None = ...,
+        where: ArrayLike | None = ...,
         step: Literal["pre", "post", "mid"] | None = ...,
         interpolate: bool = ...,
         *,

lib/matplotlib/pyplot.py

@@ -3497,7 +3497,7 @@ def fill_between(
     x: ArrayLike,
     y1: ArrayLike | float,
     y2: ArrayLike | float = 0,
-    where: Sequence[bool] | None = None,
+    where: ArrayLike | None = None,
     interpolate: bool = False,
     step: Literal["pre", "post", "mid"] | None = None,
     *,
@@ -3522,7 +3522,7 @@ def fill_betweenx(
     y: ArrayLike,
     x1: ArrayLike | float,
     x2: ArrayLike | float = 0,
-    where: Sequence[bool] | None = None,
+    where: ArrayLike | None = None,
     step: Literal["pre", "post", "mid"] | None = None,
     interpolate: bool = False,
     *,