fontforge: fix compilation without 10.7 SDK

FontForge uses the FlatCarbon headers, which are gone in Mountain
Lion. To fix this, the formula was adjusted to use the 10.7 SDK.
However, this prevents compiling FontForge on a system without the
10.7 SDK. Fix this by replacing the FlatCarbon imports with the
correct imports to the non-flat headers.

Closes Homebrew/legacy-homebrew#17909.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Formula/fontforge.rb

@@ -31,16 +31,6 @@ class Fontforge < Formula
   end
 
   def install
-    # Reason: Designed for the 10.7 SDK because it uses FlatCarbon.
-    #         MACOSX_DEPLOYMENT_TARGET fixes ensuing Python 10.7 vs 10.8 clash.
-    # Discussed: https://github.com/mxcl/homebrew/pull/14097
-    # Reported:  Not yet.
-    if MacOS.version >= :mountain_lion
-      ENV.macosxsdk("10.7")
-      ENV.append "CFLAGS", "-isysroot #{MacOS.sdk_path(10.7)}"
-      ENV["MACOSX_DEPLOYMENT_TARGET"] = "10.8"
-    end
-
     args = ["--prefix=#{prefix}",
             "--enable-double",
             "--without-freetype-bytecode"]
@@ -62,6 +52,10 @@ def install
     # Reset ARCHFLAGS to match how we build
     ENV["ARCHFLAGS"] = MacOS.prefer_64_bit? ? "-arch x86_64" : "-arch i386"
 
+    # Set up framework paths so FlatCarbon replacement paths work (see below)
+    ENV.append "CFLAGS", "-F/System/Library/Frameworks/CoreServices.framework/Frameworks"
+    ENV.append "CFLAGS", "-F/System/Library/Frameworks/Carbon.framework/Frameworks"
+
     args << "--without-cairo" unless build.with? "cairo"
     args << "--without-pango" unless build.with? "pango"
 
@@ -79,16 +73,13 @@ def install
       s.gsub! "python setup.py install --prefix=$(prefix) --root=$(DESTDIR)", "python setup.py install --prefix=$(prefix)"
     end
 
-    # Fix hard-coded include file paths. Reported usptream:
-    # http://sourceforge.net/mailarchive/forum.php?thread_name=C1A32103-A62D-468B-AD8A-A8E0E7126AA5%40smparkes.net&forum_name=fontforge-devel
-    # https://trac.macports.org/ticket/33284
-    if MacOS::Xcode.version >= '4.4'
-      header_prefix = "#{MacOS.sdk_path(10.7)}/Developer"
-    else
-      header_prefix = MacOS::Xcode.prefix
-    end
+    # Replace FlatCarbon headers with the real paths
+    # Fixes building on 10.8
     inreplace %w(fontforge/macbinary.c fontforge/startui.c gutils/giomime.c) do |s|
-      s.gsub! "/Developer", header_prefix
+      s.gsub! "/Developer/Headers/FlatCarbon/Files.h", "CarbonCore/Files.h"
+    end
+    inreplace %w(fontforge/startui.c) do |s|
+      s.gsub! "/Developer/Headers/FlatCarbon/CarbonEvents.h", "HIToolbox/CarbonEvents.h"
     end
 
     system "make"