From 0a7f42b4524b4cdfb4f8aa64c9a3d04167c9d5ca Mon Sep 17 00:00:00 2001
From: Moonchild <moonchild@palemoon.org>
Date: Fri, 2 Aug 2024 04:50:01 +0200
Subject: [PATCH] Issue #1925 - Rewrite NS_FOR_CSS_CORNERS to be similar to
 *_SIDES

- Renames it to NS_CSS_FULL_CORNERS and uses the one macro for all full
  corners. In preparation for giving half corners the same treatment.
- Swaps to prefix operator++
---
 gfx/2d/Types.h                        | 26 ++++++++++++++------------
 gfx/thebes/gfxRect.h                  |  3 ---
 layout/base/nsCSSRenderingBorders.cpp |  4 ++--
 layout/style/nsStyleConsts.h          |  2 --
 4 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/gfx/2d/Types.h b/gfx/2d/Types.h
index 882b8991f6..211577e7ab 100644
--- a/gfx/2d/Types.h
+++ b/gfx/2d/Types.h
@@ -411,26 +411,28 @@ enum Corner {
   eCornerTopLeft = 0,
   eCornerTopRight = 1,
   eCornerBottomRight = 2,
-  eCornerBottomLeft = 3,
-  eNumCorners = 4
+  eCornerBottomLeft = 3
 };
 
 #define NS_CORNER_TOP_LEFT mozilla::eCornerTopLeft
 #define NS_CORNER_TOP_RIGHT mozilla::eCornerTopRight
 #define NS_CORNER_BOTTOM_RIGHT mozilla::eCornerBottomRight
 #define NS_CORNER_BOTTOM_LEFT mozilla::eCornerBottomLeft
-#define NS_NUM_CORNERS mozilla::eNumCorners
 
-#define NS_FOR_CSS_CORNERS(var_)                       \
-  for (mozilla::Corner var_ = NS_CORNER_TOP_LEFT;      \
-       var_ <= NS_CORNER_BOTTOM_LEFT;                  \
-       var_++)
+// Creates a for loop that walks over the four mozilla::Corner values. This
+// implementation uses the same technique as NS_FOR_CSS_SIDES.
+#define NS_FOR_CSS_FULL_CORNERS(var_)                                        \
+  int32_t MOZ_CONCAT(var_,__LINE__) = mozilla::eCornerTopLeft;          \
+  for (mozilla::Corner var_;                                            \
+       MOZ_CONCAT(var_,__LINE__) <= mozilla::eCornerBottomLeft &&       \
+         (var_ = mozilla::Corner(MOZ_CONCAT(var_,__LINE__)), true);     \
+       ++MOZ_CONCAT(var_,__LINE__))
 
-static inline mozilla::Corner operator++(mozilla::Corner& corner, int) {
-  MOZ_ASSERT(corner >= NS_CORNER_TOP_LEFT &&
-             corner < NS_NUM_CORNERS, "Out of range corner");
-  corner = mozilla::Corner(corner + 1);
-  return corner;
+static inline mozilla::Corner operator++(mozilla::Corner& aCorner) {
+  MOZ_ASSERT(aCorner >= eCornerTopLeft && aCorner <= eCornerBottomLeft,
+             "Out of range corner!");
+  aCorner = mozilla::Corner(aCorner + 1);
+  return aCorner;
 }
 
 } // namespace mozilla
diff --git a/gfx/thebes/gfxRect.h b/gfx/thebes/gfxRect.h
index 780b91f22c..dd0e500119 100644
--- a/gfx/thebes/gfxRect.h
+++ b/gfx/thebes/gfxRect.h
@@ -51,9 +51,6 @@ struct gfxRect :
             case NS_CORNER_TOP_RIGHT: return TopRight();
             case NS_CORNER_BOTTOM_RIGHT: return BottomRight();
             case NS_CORNER_BOTTOM_LEFT: return BottomLeft();
-            default:
-                NS_ERROR("Invalid corner!");
-                break;
         }
         return gfxPoint(0.0, 0.0);
     }
diff --git a/layout/base/nsCSSRenderingBorders.cpp b/layout/base/nsCSSRenderingBorders.cpp
index e786cc5e0d..27758bcc0c 100644
--- a/layout/base/nsCSSRenderingBorders.cpp
+++ b/layout/base/nsCSSRenderingBorders.cpp
@@ -3385,7 +3385,7 @@ nsCSSBorderRenderer::DrawBorders()
      * a 1.0 unit border all around and no border radius.
      */
 
-    NS_FOR_CSS_CORNERS(corner) {
+    NS_FOR_CSS_FULL_CORNERS(corner) {
       const mozilla::Side sides[2] = { mozilla::Side(corner), PREV_SIDE(corner) };
 
       if (!IsZeroSize(mBorderRadii[corner]))
@@ -3400,7 +3400,7 @@ nsCSSBorderRenderer::DrawBorders()
     }
 
     // First, the corners
-    NS_FOR_CSS_CORNERS(corner) {
+    NS_FOR_CSS_FULL_CORNERS(corner) {
       // if there's no corner, don't do all this work for it
       if (IsZeroSize(mBorderCornerDimensions[corner]))
         continue;
diff --git a/layout/style/nsStyleConsts.h b/layout/style/nsStyleConsts.h
index 90ead02e67..9465052321 100644
--- a/layout/style/nsStyleConsts.h
+++ b/layout/style/nsStyleConsts.h
@@ -16,8 +16,6 @@
 
 namespace mozilla {
 
-#define NS_FOR_CSS_FULL_CORNERS(var_) for (int32_t var_ = 0; var_ < 4; ++var_)
-
 // Indices into "half corner" arrays (nsStyleCorners e.g.)
 #define NS_CORNER_TOP_LEFT_X      0
 #define NS_CORNER_TOP_LEFT_Y      1