File dont_round_font_scaling.patch of Package MozillaThunderbird

diff --git a/gfx/thebes/gfxPlatformGtk.cpp b/gfx/thebes/gfxPlatformGtk.cpp
--- a/gfx/thebes/gfxPlatformGtk.cpp
+++ b/gfx/thebes/gfxPlatformGtk.cpp
@@ -477,32 +477,13 @@
   sDPI = dpi;
   return dpi;
 }
 
 double gfxPlatformGtk::GetFontScaleFactor() {
-  // Integer scale factors work well with GTK window scaling, image scaling, and
-  // pixel alignment, but there is a range where 1 is too small and 2 is too
-  // big.
-  //
-  // An additional step of 1.5 is added because this is common scale on WINNT
-  // and at this ratio the advantages of larger rendering outweigh the
-  // disadvantages from scaling and pixel mis-alignment.
-  //
-  // A similar step for 1.25 is added as well, because this is the scale that
-  // "Large text" settings use in gnome, and it seems worth to allow, especially
-  // on already-hidpi environments.
-  int32_t dpi = GetFontScaleDPI();
-  if (dpi < 120) {
-    return 1.0;
-  }
-  if (dpi < 132) {
-    return 1.25;
-  }
-  if (dpi < 168) {
-    return 1.5;
-  }
-  return round(dpi / 96.0);
+  // Modern GTK works fine with non-integer scaling, and scaling factors like
+  // 1.25 are common as "Large text" in gnome as well, so no need to round.
+  return GetFontScaleDPI() / 96.0;
 }
 
 gfxImageFormat gfxPlatformGtk::GetOffscreenFormat() {
   // Make sure there is a screen
   GdkScreen* screen = gdk_screen_get_default();