Improved the error diagnosis, after seeing...

Improved the error diagnosis, after seeing http://www.nabble.com/error-installing-hudson-as-a-windows-service-tt21378003.html

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@14320 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/util/jna/DotNet.java

@@ -13,25 +13,31 @@ public class DotNet {
      * Returns true if the .NET framework of the given version (or greater) is installed.
      */
     public static boolean isInstalled(int major, int minor) {
-        // see http://support.microsoft.com/?scid=kb;en-us;315291 for the basic algorithm
-        // observation in my registry shows that the actual key name can be things like "v2.0 SP1"
-        // or "v2.0.50727", so the regexp is written to accomodate this.
-        RegistryKey key = RegistryKey.LOCAL_MACHINE.openReadonly("SOFTWARE\\Microsoft\\.NETFramework");
         try {
-            for( String keyName : key.getSubKeys() ) {
-                Matcher m = VERSION_PATTERN.matcher(keyName);
-                if(m.matches()) {
-                    int mj = Integer.parseInt(m.group(1));
-                    if(mj>=major) {
-                        int mn = Integer.parseInt(m.group(2));
-                        if(mn>=minor)
-                            return true;
+// see http://support.microsoft.com/?scid=kb;en-us;315291 for the basic algorithm
+            // observation in my registry shows that the actual key name can be things like "v2.0 SP1"
+            // or "v2.0.50727", so the regexp is written to accomodate this.
+            RegistryKey key = RegistryKey.LOCAL_MACHINE.openReadonly("SOFTWARE\\Microsoft\\.NETFramework");
+            try {
+                for( String keyName : key.getSubKeys() ) {
+                    Matcher m = VERSION_PATTERN.matcher(keyName);
+                    if(m.matches()) {
+                        int mj = Integer.parseInt(m.group(1));
+                        if(mj>=major) {
+                            int mn = Integer.parseInt(m.group(2));
+                            if(mn>=minor)
+                                return true;
+                        }
                     }
                 }
+                return false;
+            } finally {
+                key.dispose();
             }
-            return false;
-        } finally {
-            key.dispose();
+        } catch (JnaException e) {
+            if(e.getErrorCode()==2) // thrown when openReadonly fails because the key doesn't exist.
+                return false;
+            throw e;
         }
     }
 

core/src/main/java/hudson/util/jna/JnaException.java

@@ -8,7 +8,14 @@ import hudson.Util;
  * @author Kohsuke Kawaguchi
  */
 public class JnaException extends RuntimeException {
+    private final int errorCode;
+
     public JnaException(int errorCode) {
         super("Win32 error: "+errorCode+" - "+Util.getWin32ErrorMessage(errorCode));
+        this.errorCode = errorCode;
+    }
+
+    public int getErrorCode() {
+        return errorCode;
     }
 }