clarified ISABELLE_JDK_HOME: derive from running JVM, but ignore accidental JAVA_HOME;
clarified jEdit/README_BUILD;

--- a/NEWS	Wed Mar 28 13:38:56 2012 +0200
+++ b/NEWS	Wed Mar 28 13:53:30 2012 +0200
@@ -48,8 +48,7 @@
 commands to be used in the same theory where defined.
 
 * ISABELLE_JDK_HOME settings variable points to JDK with javac and jar
-(not just JRE), derived from JAVA_HOME from the shell environment or
-java.home of the running JVM.
+(not just JRE).
 
 
 *** Pure ***

--- a/etc/settings	Wed Mar 28 13:38:56 2012 +0200
+++ b/etc/settings	Wed Mar 28 13:53:30 2012 +0200
@@ -54,14 +54,6 @@
 ### JVM components (Scala or Java)
 ###
 
-if [ -z "$ISABELLE_JDK_HOME" -a -n "$JAVA_HOME" ]; then
-  if [ "$(basename "$JAVA_HOME")" = jre -a -e "$(dirname "$JAVA_HOME")"/bin/javac ]; then
-    ISABELLE_JDK_HOME="$(dirname "$JAVA_HOME")"
-  else
-    ISABELLE_JDK_HOME="$JAVA_HOME"
-  fi
-fi
-
 ISABELLE_SCALA_BUILD_OPTIONS="-nowarn -target:jvm-1.5"
 
 

--- a/src/Tools/jEdit/README_BUILD	Wed Mar 28 13:38:56 2012 +0200
+++ b/src/Tools/jEdit/README_BUILD	Wed Mar 28 13:53:30 2012 +0200
@@ -18,9 +18,11 @@
 Important settings within Isabelle environment
 ==============================================
 
-- JAVA_HOME
-- SCALA_HOME
-- ISABELLE_JEDIT_BUILD_HOME (via "init_component .../jedit_build...")
+* init_component ".../jedit_build-20120327"
+* ISABELLE_JDK_HOME
+* SCALA_HOME
+
+Note that the official directory layout of JDK and Scala is required!
 
 
 Build and run
@@ -28,15 +30,3 @@
 
 isabelle jedit -l HOL Test.thy
 
-
------------------------------------------------------------------------
-To run jedit with remote debugging enabled, I use the following
-command: "java
--agentlib:jdwp=transport=dt_socket,suspend=y,server=y,address=XXXX
--jar jedit.jar"
-
-where XXXX is any open port number you wish. The above invocation
-works for Sun's JDK 5.0.  There's an alternate incantation for earlier
-releases. (See
-http://java.sun.com/j2se/1.5.0/docs/guide/jpda/conninv.html)
------------------------------------------------------------------------