File mozilla-landscape_printing.patch of Package MozillaFirefox.2166

# HG changeset patch
# Parent  548ea0216c0d35b5eac28815df6cdf41353b9806
Handle printing in landscape orientation properly.
Modified from bmo#1120490 - mozilla-central changeset 036e241fd1b4

Also see bsc#908275

diff --git a/gfx/src/nsDeviceContext.cpp b/gfx/src/nsDeviceContext.cpp
--- a/gfx/src/nsDeviceContext.cpp
+++ b/gfx/src/nsDeviceContext.cpp
@@ -411,17 +411,30 @@ nsDeviceContext::CreateRenderingContext(
                                                              gfx::IntSize(mWidth, mHeight));
 
 #ifdef XP_MACOSX
     dt->AddUserData(&gfxContext::sDontUseAsSourceKey, dt, nullptr);
 #endif
     dt->AddUserData(&sDisablePixelSnapping, (void*)0x1, nullptr);
 
     nsRefPtr<gfxContext> pContext = new gfxContext(dt);
-    pContext->SetMatrix(gfxMatrix::Scaling(mPrintingScale, mPrintingScale));
+
+    gfxMatrix transform;
+    if (printingSurface->GetRotateForLandscape()) {
+      // Rotate page 90 degrees CW aroung the origin and move the result by its
+      // height to draw landscape page on portrait paper
+      // (the Y axis grows downwards, hence the opposite sign for rotation)
+      gfxMatrix rotate(  0,  1,
+                        -1,  0,
+                       printingSurface->GetSize().height, 0);
+      transform *= rotate;
+    }
+    transform.Scale(mPrintingScale, mPrintingScale);
+
+    pContext->SetMatrix(transform);
     return pContext.forget();
 }
 
 nsresult
 nsDeviceContext::GetDepth(uint32_t& aDepth)
 {
     if (mDepth == 0 && mScreenManager) {
         nsCOMPtr<nsIScreen> primaryScreen;