Index: lib/Driver/ToolChains/Gnu.cpp
===================================================================
--- lib/Driver/ToolChains/Gnu.cpp
+++ lib/Driver/ToolChains/Gnu.cpp
@@ -1594,21 +1594,29 @@
   GoodVersion.MajorStr = First.first.str();
   if (First.second.empty())
     return GoodVersion;
-  if (Second.first.getAsInteger(10, GoodVersion.Minor) || GoodVersion.Minor < 0)
+  StringRef MinorStr = Second.first;
+  if (Second.second.empty()) {
+    if (size_t EndNumber = MinorStr.find_first_not_of("0123456789")) {
+      GoodVersion.PatchSuffix = MinorStr.substr(EndNumber);
+      MinorStr = MinorStr.slice(0, EndNumber);
+    }
+  }
+  if (MinorStr.getAsInteger(10, GoodVersion.Minor) || GoodVersion.Minor < 0)
     return BadVersion;
-  GoodVersion.MinorStr = Second.first.str();
+  GoodVersion.MinorStr = MinorStr.str();
 
   // First look for a number prefix and parse that if present. Otherwise just
   // stash the entire patch string in the suffix, and leave the number
   // unspecified. This covers versions strings such as:
   //   5        (handled above)
   //   4.4
+  //   4.4-patched
   //   4.4.0
   //   4.4.x
   //   4.4.2-rc4
   //   4.4.x-patched
   // And retains any patch number it finds.
-  StringRef PatchText = GoodVersion.PatchSuffix = Second.second.str();
+  StringRef PatchText = Second.second.str();
   if (!PatchText.empty()) {
     if (size_t EndNumber = PatchText.find_first_not_of("0123456789")) {
       // Try to parse the number and any suffix.
Index: test/Driver/mingw.cpp
===================================================================
--- test/Driver/mingw.cpp
+++ test/Driver/mingw.cpp
@@ -49,3 +49,10 @@
 // CHECK_MINGW_UBUNTU_TREE: "{{.*}}/Inputs/mingw_ubuntu_tree/usr{{/|\\\\}}include{{/|\\\\}}c++{{/|\\\\}}4.8{{/|\\\\}}x86_64-w64-mingw32"
 // CHECK_MINGW_UBUNTU_TREE: "{{.*}}/Inputs/mingw_ubuntu_tree/usr{{/|\\\\}}include{{/|\\\\}}c++{{/|\\\\}}4.8{{/|\\\\}}backward"
 // CHECK_MINGW_UBUNTU_TREE: "{{.*}}/Inputs/mingw_ubuntu_tree/usr{{/|\\\\}}x86_64-w64-mingw32{{/|\\\\}}include"
+
+
+// RUN: %clang -target x86_64-pc-windows-gnu -rtlib=platform -stdlib=libstdc++ -c -### --sysroot=%S/Inputs/mingw_ubuntu_posix_tree/usr %s 2>&1 | FileCheck -check-prefix=CHECK_MINGW_UBUNTU_POSIX_TREE %s
+// CHECK_MINGW_UBUNTU_POSIX_TREE: "{{.*}}/Inputs/mingw_ubuntu_posix_tree/usr{{/|\\\\}}lib{{/|\\\\}}gcc{{/|\\\\}}x86_64-w64-mingw32{{/|\\\\}}5.3-posix{{/|\\\\}}include{{/|\\\\}}c++"
+// CHECK_MINGW_UBUNTU_POSIX_TREE: "{{.*}}/Inputs/mingw_ubuntu_posix_tree/usr{{/|\\\\}}lib{{/|\\\\}}gcc{{/|\\\\}}x86_64-w64-mingw32{{/|\\\\}}5.3-posix{{/|\\\\}}include{{/|\\\\}}c++{{/|\\\\}}x86_64-w64-mingw32"
+// CHECK_MINGW_UBUNTU_POSIX_TREE: "{{.*}}/Inputs/mingw_ubuntu_posix_tree/usr{{/|\\\\}}lib{{/|\\\\}}gcc{{/|\\\\}}x86_64-w64-mingw32{{/|\\\\}}5.3-posix{{/|\\\\}}include{{/|\\\\}}c++{{/|\\\\}}backward"
+// CHECK_MINGW_UBUNTU_POSIX_TREE: "{{.*}}/Inputs/mingw_ubuntu_posix_tree/usr{{/|\\\\}}x86_64-w64-mingw32{{/|\\\\}}include"