RFR [9] 8139297: java.lang.NoClassDefFoundError: Could not initialize class jdk.internal.jimage.ImageNativeSubstrate

[Chris Hegarty]

This is a little temporary solution to get the jrt-fs up and running again
with JDK 8, until JDK-8137017 [1] can be resolved.

It is fair game for an unchecked Exception or Error thrown during
class initialization to result in a NCDFE. The code in BasicImageReader 
should catch java.lang.LinkageError, rather than UnsatisfiedLinkError 
( LinkageError is the supertype of NCDFE and UnsatisfiedLinkError ),
so that it falls over the the Java implementation when libjimage is not
in the runtime image.

diff --git a/src/java.base/share/classes/jdk/internal/jimage/BasicImageReader.java b/src/java.base/share/classes/jdk/internal/jimage/BasicImageReader.java
--- a/src/java.base/share/classes/jdk/internal/jimage/BasicImageReader.java
+++ b/src/java.base/share/classes/jdk/internal/jimage/BasicImageReader.java
@@ -58,7 +58,7 @@
 
         try {
             substrate = ImageNativeSubstrate.openImage(imagePath, byteOrder);
-        } catch (UnsatisfiedLinkError ex) {
+        } catch (LinkageError ex) {
             substrate = ImageJavaSubstrate.openImage(imagePath, byteOrder);
         }

-Chris.

[1] https://bugs.openjdk.java.net/browse/JDK-8137017