python: Fix inequality comparisons

On Python 3, executing `foo != bar` will first try to call
foo.__ne__(bar), and fallback on the opposite result of foo.__eq__(bar).

Python 2 does not do that.

As a result, those __eq__ methods were never called, when we were
testing for inequality.

Expliclty adding the __ne__ methods fixes this issue, in a way that is
compatible with both Python 2 and 3.

However, this means the __eq__ methods are now called when testing for
`foo != None`, so they need to be guarded correctly.

Signed-off-by: Mathieu Bridon <[email protected]>
Reviewed-by: Dylan Baker <[email protected]>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_format_parse.py b/src/gallium/auxiliary/util/u_format_parse.py
index d3874cd895b..48cc012cd2a 100644
--- a/src/gallium/auxiliary/util/u_format_parse.py
+++ b/src/gallium/auxiliary/util/u_format_parse.py
@@ -72,8 +72,14 @@ class Channel:
         return s
 
     def __eq__(self, other):
+        if other is None:
+            return False
+
         return self.type == other.type and self.norm == other.norm and self.pure == other.pure and self.size == other.size
 
+    def __ne__(self, other):
+        return not self == other
+
     def max(self):
         '''Maximum representable number.'''
         if self.type == FLOAT: