From d219231de5e85debee4ecf429a73bf562657e03d Mon Sep 17 00:00:00 2001
From: Hans Wennborg <hans@hanshq.net>
Date: Thu, 10 Oct 2013 18:03:08 +0000
Subject: [PATCH] Locate VS InstallDir in the presence of newer runtime

This fixes getSystemRegistryString() in WindowsToolChain.cpp to
make sure that the VS version that it picks has an InstallDir.
Previously we would look for the highest version os VS and check
for InstallDir afterwards.

Patch by Yaron Keren!

llvm-svn: 192374
---
 clang/lib/Driver/WindowsToolChain.cpp | 39 +++++++++++++--------------
 1 file changed, 19 insertions(+), 20 deletions(-)

diff --git a/clang/lib/Driver/WindowsToolChain.cpp b/clang/lib/Driver/WindowsToolChain.cpp
index ad84d02f5981..db36f1eba713 100644
--- a/clang/lib/Driver/WindowsToolChain.cpp
+++ b/clang/lib/Driver/WindowsToolChain.cpp
@@ -146,30 +146,29 @@ static bool getSystemRegistryString(const char *keyPath, const char *valueName,
         char numBuf[32];
         strncpy(numBuf, sp, sizeof(numBuf) - 1);
         numBuf[sizeof(numBuf) - 1] = '\0';
-        double value = strtod(numBuf, NULL);
-        if (value > bestValue) {
-          bestIndex = (int)index;
-          bestValue = value;
+        double dvalue = strtod(numBuf, NULL);
+        if (dvalue > bestValue) {
+          // Test that InstallDir is indeed there before keeping this index.
+          // Open the chosen key path remainder.
           strcpy(bestName, keyName);
+          // Append rest of key.
+          strncat(bestName, nextKey, sizeof(bestName) - 1);
+          bestName[sizeof(bestName) - 1] = '\0';
+          lResult = RegOpenKeyEx(hTopKey, bestName, 0,
+                                 KEY_READ | KEY_WOW64_32KEY, &hKey);
+          if (lResult == ERROR_SUCCESS) {
+            lResult = RegQueryValueEx(hKey, valueName, NULL, &valueType,
+              (LPBYTE)value, &valueSize);
+            if (lResult == ERROR_SUCCESS) {
+              bestIndex = (int)index;
+              bestValue = dvalue;
+              returnValue = true;
+            }
+            RegCloseKey(hKey);
+          }
         }
         size = sizeof(keyName) - 1;
       }
-      // If we found the highest versioned key, open the key and get the value.
-      if (bestIndex != -1) {
-        // Append rest of key.
-        strncat(bestName, nextKey, sizeof(bestName) - 1);
-        bestName[sizeof(bestName) - 1] = '\0';
-        // Open the chosen key path remainder.
-        lResult = RegOpenKeyEx(hTopKey, bestName, 0, KEY_READ | KEY_WOW64_32KEY,
-                               &hKey);
-        if (lResult == ERROR_SUCCESS) {
-          lResult = RegQueryValueEx(hKey, valueName, NULL, &valueType,
-            (LPBYTE)value, &valueSize);
-          if (lResult == ERROR_SUCCESS)
-            returnValue = true;
-          RegCloseKey(hKey);
-        }
-      }
       RegCloseKey(hTopKey);
     }
   } else {