Index: tools/build/v2/tools/fop.jam
===================================================================
--- tools/build/v2/tools/fop.jam	(revision 66265)
+++ tools/build/v2/tools/fop.jam	(working copy)
@@ -9,7 +9,8 @@
 import os ;
 import generators ;
 import common ;
-import errors ; 
+import errors ;
+import boostbook ;
 
 generators.register-standard fop.render.pdf : FO : PDF ;
 generators.register-standard fop.render.ps : FO : PS ;
@@ -21,19 +22,35 @@
         
     if $(.initialized)
     {
-        if $(.FOP_COMMAND) != $(fop-command) || $(JAVA_HOME) != $(java-home)
-           || $(JAVACMD) != $(java)
+        if $(.FOP_COMMAND) != $(fop-command) || $(.JAVA_HOME) != $(java-home)
+           || $(.JAVACMD) != $(java)
         {
             errors.user-error "fop: reinitialization with different options" ;
         }        
     }
     else
     {
+        # Save the parameters to check if reinitialized.
         .initialized = true ;
         .FOP_COMMAND = $(fop-command) ;
-        # What is the meaning of this logic?  Needs more comments!!  --DWA
-        java-home ?= $(java) ;
-        .FOP_SETUP = [ common.variable-setting-command JAVA_HOME : $(java-home) ] ;
+        .JAVA_HOME = $(java-home) ;
+        .JAVACMD = $(java) ;
+        
+        # JAVA_HOME is the location that java was installed to.
+        
+        if $(java-home)
+        {
+            .FOP_SETUP += [ common.variable-setting-command JAVA_HOME : $(java-home) ] ;
+        }
+
+        # JAVACMD is the location that of the java executable, useful for a
+        # non-standard java installation, where the executable isn't at
+        # $JAVA_HOME/bin/java.
+        
+        if $(java)
+        {
+            .FOP_SETUP += [ common.variable-setting-command JAVACMD : $(java) ] ;
+        }
     }
     
     # Make sure the fop command is executed from within the directory where it's located.