Index: build.xml
===================================================================
--- a/build.xml	(revision 115)
+++ b/build.xml	(working copy)
@@ -1,15 +1,14 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project name="aDosBox" default="help">
 
-<!-- The local.properties file is created and updated by the 'android'
-     tool.
-     It contains the path to the SDK. It should *NOT* be checked into
-     Version Control Systems. -->
+    <!-- The local.properties file is created and updated by the 'android' tool.
+         It contains the path to the SDK. It should *NOT* be checked into
+         Version Control Systems. -->
     <property file="local.properties" />
 
-    <!-- The build.properties file can be created by you and is never touched
-         by the 'android' tool. This is the place to change some of the
-         default property values used by the Ant rules.
+    <!-- The ant.properties file can be created by you. It is only edited by the
+         'android' tool to add properties to it.
+         This is the place to change some Ant specific build properties.
          Here are some properties you may want to change/update:
 
          source.dir
@@ -17,6 +16,9 @@
          out.dir
              The name of the output directory. Default is 'bin'.
 
+         For other overridable properties, look at the beginning of the rules
+         files in the SDK, at tools/ant/build.xml
+
          Properties related to the SDK location or the project target should
          be updated using the 'android' tool with the 'update' action.
 
@@ -24,56 +26,67 @@
          application and should be checked into Version Control Systems.
 
          -->
-    <property file="build.properties" />
+    <property file="ant.properties" />
 
-    <!-- The default.properties file is created and updated by the 'android'
+    <!-- if sdk.dir was not set from one of the property file, then
+         get it from the ANDROID_HOME env var.
+         This must be done before we load project.properties since
+         the proguard config can use sdk.dir -->
+    <property environment="env" />
+    <condition property="sdk.dir" value="${env.ANDROID_HOME}">
+        <isset property="env.ANDROID_HOME" />
+    </condition>
+
+    <!-- The project.properties file is created and updated by the 'android'
          tool, as well as ADT.
+
+         This contains project specific properties such as project target, and library
+         dependencies. Lower level build properties are stored in ant.properties
+         (or in .classpath for Eclipse projects).
+
          This file is an integral part of the build system for your
          application and should be checked into Version Control Systems. -->
-    <property file="default.properties" />
+    <loadproperties srcFile="project.properties" />
 
+    <!-- quick check on sdk.dir -->
+    <fail
+            message="sdk.dir is missing. Make sure to generate local.properties using 'android update project' or to inject it through the ANDROID_HOME environment variable."
+            unless="sdk.dir"
+    />
 
-    <!-- Required pre-setup import -->
-    <import file="${sdk.dir}/tools/ant/pre_setup.xml" />
+    <!--
+        Import per project custom build rules if present at the root of the project.
+        This is the place to put custom intermediary targets such as:
+            -pre-build
+            -pre-compile
+            -post-compile (This is typically used for code obfuscation.
+                           Compiled code location: ${out.classes.absolute.dir}
+                           If this is not done in place, override ${out.dex.input.absolute.dir})
+            -post-package
+            -post-build
+            -pre-clean
+    -->
+    <import file="custom_rules.xml" optional="true" />
 
+    <!-- Import the actual build file.
 
-<!-- extension targets. Uncomment the ones where you want to do custom work
-     in between standard targets -->
-<!--
-    <target name="-pre-build">
-    </target>
-    <target name="-pre-compile">
-    </target>
-
-    [This is typically used for code obfuscation.
-     Compiled code location: ${out.classes.absolute.dir}
-     If this is not done in place, override ${out.dex.input.absolute.dir}]
-    <target name="-post-compile">
-    </target>
--->
-
-    <!-- Execute the Android Setup task that will setup some properties
-         specific to the target, and import the build rules files.
-
-         The rules file is imported from
-            <SDK>/tools/ant/
-         Depending on the project type it can be either:
-         - main_rules.xml
-         - lib_rules.xml
-         - test_rules.xml
-
          To customize existing targets, there are two options:
          - Customize only one target:
              - copy/paste the target into this file, *before* the
-               <setup> task.
+               <import> task.
              - customize it to your needs.
-         - Customize the whole script.
+         - Customize the whole content of build.xml
              - copy/paste the content of the rules files (minus the top node)
-               into this file, *after* the <setup> task
-             - disable the import of the rules by changing the setup task
-               below to <setup import="false" />.
+               into this file, replacing the <import> task.
              - customize to your needs.
+
+         ***********************
+         ****** IMPORTANT ******
+         ***********************
+         In all cases you must update the value of version-tag below to read 'custom' instead of an integer,
+         in order to avoid having your file be overridden by tools such as "android update project"
     -->
-    <setup />
+    <!-- version-tag: 1 -->
+    <import file="${sdk.dir}/tools/ant/build.xml" />
 
 </project>