diff --git a/mozilla/build/mac/BuildNGLayout.pl b/mozilla/build/mac/BuildNGLayout.pl
index 5557e0064b6..bc158f88e1d 100644
--- a/mozilla/build/mac/BuildNGLayout.pl
+++ b/mozilla/build/mac/BuildNGLayout.pl
@@ -75,9 +75,24 @@ $options{mng}			= 1;
 $options{ldap}			= 0;
 $options{xmlextras}		= 0;
 
-$options{jar_manifests} = 1;        # use jar.mn files for resources, not MANIFESTs
-$options{jars}    		= 1;        # build jar files
-$options{chrome_files}  = 0;        # install files in chrome as well as making jar files.
+# -------------------------- Chrome and jar-related options -----------------------------------------
+
+$options{jar_manifests} = 1;        # use jar.mn files for resources, not MANIFESTs. This must be ON,
+                                    # unless you want to use the obsolete (and probably bitrotted)
+                                    # MANIFEST files to install resources.
+
+
+# These two options determine whether you get jar files, or loose files in chrome.
+# Either one or both option must be turned on.
+                                                                        
+$options{chrome_jars}   = 1;        # build jar files
+$options{chrome_files}  = 0;        # install regular files in chrome
+
+$options{use_jars}      = 1;        # This option determines whether chrome comes out of jars
+                                    # or regular files at runtime (by affecting installed-chrome.txt).
+                                    # If 1, $options{chrome_jars} must be 1.
+
+# ------------------------ End chrome and jar-related options ----------------------------------------
 
 # Don't change these (where should they go?)
 $optiondefines{mathml}{MOZ_MATHML}		= 1;
diff --git a/mozilla/build/mac/BuildNGLayoutDebug.pl b/mozilla/build/mac/BuildNGLayoutDebug.pl
index 88451e19bd6..18c723ed00c 100644
--- a/mozilla/build/mac/BuildNGLayoutDebug.pl
+++ b/mozilla/build/mac/BuildNGLayoutDebug.pl
@@ -29,123 +29,137 @@ use NGLayoutBuildList;
 use Cwd;
 use Moz;
 
-$DEBUG					= 1;
-$CARBON					= 0;	# Turn on to build with TARGET_CARBON
-$PROFILE				= 0;
-$GC_LEAK_DETECTOR		= 0;	# turn on to use GC leak detection
-$INCLUDE_CLASSIC_SKIN = 1;
+$DEBUG                  = 1;
+$CARBON                 = 0;    # Turn on to build with TARGET_CARBON
+$PROFILE                = 0;
+$GC_LEAK_DETECTOR       = 0;    # turn on to use GC leak detection
+$INCLUDE_CLASSIC_SKIN   = 1;
 
-$pull{all} 				= 0;
-$pull{moz}				= 0;
-$pull{runtime} 			= 0;
+$pull{all}              = 0;
+$pull{moz}              = 0;
+$pull{runtime}          = 0;
 
-$build{all} 			= 1;	# Turn off to do individual builds, or to do "most"
-$build{most} 			= 0;	# Turn off to do individual builds
-$build{dist} 			= 0;
-$build{dist_runtime}	= 0;	# Implied by $build{dist}
-$build{xpidl}			= 0;
+$build{all}             = 1;    # Turn off to do individual builds, or to do "most"
+$build{most}            = 0;    # Turn off to do individual builds
+$build{dist}            = 0;
+$build{dist_runtime}    = 0;    # Implied by $build{dist}
+$build{xpidl}           = 0;
 $build{idl}             = 0;
-$build{stubs} 			= 0;
-$build{runtime}			= 0;
-$build{common} 			= 0;
-$build{imglib} 			= 0;
-$build{necko} 			= 0;
+$build{stubs}           = 0;
+$build{runtime}         = 0;
+$build{common}          = 0;
+$build{imglib}          = 0;
+$build{necko}           = 0;
 $build{security}        = 0;
-$build{browserutils} 	= 0;
-$build{intl} 			= 0;
-$build{nglayout} 		= 0;
-$build{editor} 			= 0;
-$build{viewer} 			= 0;
-$build{xpapp} 			= 0;
-$build{extensions} 		= 1;
-$build{plugins}			= 0;
-$build{mailnews} 		= 0;
-$build{apprunner}		= 0;
-$build{resources} 		= 1;
+$build{browserutils}    = 0;
+$build{intl}            = 0;
+$build{nglayout}        = 0;
+$build{editor}          = 0;
+$build{viewer}          = 0;
+$build{xpapp}           = 0;
+$build{extensions}      = 1;
+$build{plugins}         = 0;
+$build{mailnews}        = 0;
+$build{apprunner}       = 0;
+$build{resources}       = 1;
 
-$build{xptlink}		    = 0;
+$build{xptlink}         = 0;
 
-$options{transformiix}	= 0;
-$options{mathml}		= 0;
-$options{svg}			= 0;
-$options{mng}			= 1;
-$options{ldap}			= 0;
-$options{xmlextras}		= 0;
+$options{transformiix}  = 0;
+$options{mathml}        = 0;
+$options{svg}           = 0;
+$options{mng}           = 1;
+$options{ldap}          = 0;
+$options{xmlextras}     = 0;
 
-$options{jar_manifests} = 1;        # use jar.mn files for resources, not MANIFESTs
-$options{jars}    		= 1;        # build jar files
-$options{chrome_files}  = 0;        # install files in chrome as well as making jar files.
+# -------------------------- Chrome and jar-related options -----------------------------------------
 
+$options{jar_manifests} = 1;        # use jar.mn files for resources, not MANIFESTs. This must be ON,
+                                    # unless you want to use the obsolete (and probably bitrotted)
+                                    # MANIFEST files to install resources.
+
+
+# These two options determine whether you get jar files, or loose files in chrome.
+# Either one or both option must be turned on.
+                                                                        
+$options{chrome_jars}   = 1;        # build jar files
+$options{chrome_files}  = 0;        # install regular files in chrome
+
+$options{use_jars}      = 1;        # This option determines whether chrome comes out of jars
+                                    # or regular files at runtime (by affecting installed-chrome.txt).
+                                    # If 1, $options{chrome_jars} must be 1.
+
+# ------------------------ End chrome and jar-related options ----------------------------------------
 
 # Don't change these (where should they go?)
-$optiondefines{mathml}{MOZ_MATHML}		= 1;
-$optiondefines{svg}{MOZ_SVG}			= 1;
+$optiondefines{mathml}{MOZ_MATHML}      = 1;
+$optiondefines{svg}{MOZ_SVG}            = 1;
 
 #-----------------------------------------------
 # configuration variables that affect the manner
 # of building, but possibly affecting
 # the outcome.
 #-----------------------------------------------
-$ALIAS_SYM_FILES		= $DEBUG;
-$CLOBBER_LIBS			= 1;	# turn on to clobber existing libs and .xSYM files before
-								# building each project							
+$ALIAS_SYM_FILES        = $DEBUG;
+$CLOBBER_LIBS           = 1;    # turn on to clobber existing libs and .xSYM files before
+                                # building each project                         
 # The following two options will delete all dist files (if you have $build{dist} turned on),
 # but leave the directory structure intact.
-$CLOBBER_DIST_ALL 		= 1;	# turn on to clobber all aliases/files inside dist (headers/xsym/libs)
-$CLOBBER_DIST_LIBS 		= 0;	# turn on to clobber only aliases/files for libraries/sym files in dist
-$CLOBBER_IDL_PROJECTS	= 0;	# turn on to clobber all IDL projects.
+$CLOBBER_DIST_ALL       = 1;    # turn on to clobber all aliases/files inside dist (headers/xsym/libs)
+$CLOBBER_DIST_LIBS      = 0;    # turn on to clobber only aliases/files for libraries/sym files in dist
+$CLOBBER_IDL_PROJECTS   = 0;    # turn on to clobber all IDL projects.
 
 #-----------------------------------------------
 # configuration variables that are preferences for the build style,
 # and do not affect what is built.
 #-----------------------------------------------
 $CodeWarriorLib::CLOSE_PROJECTS_FIRST
-						= 1;
-								# 1 = close then make (for development),
-								# 0 = make then close (for tinderbox).
-$USE_TIMESTAMPED_LOGS 	= 1;
+                        = 1;
+                                # 1 = close then make (for development),
+                                # 0 = make then close (for tinderbox).
+$USE_TIMESTAMPED_LOGS   = 1;
 #-----------------------------------------------
 # END OF CONFIG SWITCHES
 #-----------------------------------------------
 
 if ($pull{all})
 {
-	foreach $k (keys(%pull))
-	{
-		$pull{$k} = 1;
-	}
+    foreach $k (keys(%pull))
+    {
+        $pull{$k} = 1;
+    }
 }
 if ($build{all})
 {
-	foreach $k (keys(%build))
-	{
-		$build{$k} = 1;
-	}
+    foreach $k (keys(%build))
+    {
+        $build{$k} = 1;
+    }
 }
 if ($build{most})
 {
 ### Just uncomment/comment to get the ones you want (if "most" is selected).
-#	$build{dist}		= 1;
-#	$build{dist_runtime}= 1;
-    $build{xpidl}		= 1; # build idl compiler
-	$build{idl}         = 1;
-	$build{stubs}		= 1;
-	$build{runtime}		= 1;
-	$build{common}		= 1;
-	$build{imglib} 		= 1;
-	$build{necko} 		= 1;
+#   $build{dist}        = 1;
+#   $build{dist_runtime}= 1;
+    $build{xpidl}       = 1; # build idl compiler
+    $build{idl}         = 1;
+    $build{stubs}       = 1;
+    $build{runtime}     = 1;
+    $build{common}      = 1;
+    $build{imglib}      = 1;
+    $build{necko}       = 1;
     $build{security}    = 1;
-	$build{browserutils} = 1;
-	$build{intl}		= 1; 
-	$build{nglayout}	= 1;
-	$build{editor}		= 1;
-	$build{viewer}		= 1;
-	$build{xpapp}		= 1;
-	$build{extensions} 	= 1;
-	$build{plugins}		= 1;
-	$build{mailnews}	= 1;
-	$build{apprunner} 	= 1;
-	$build{resources}	= 1;
+    $build{browserutils} = 1;
+    $build{intl}        = 1; 
+    $build{nglayout}    = 1;
+    $build{editor}      = 1;
+    $build{viewer}      = 1;
+    $build{xpapp}       = 1;
+    $build{extensions}  = 1;
+    $build{plugins}     = 1;
+    $build{mailnews}    = 1;
+    $build{apprunner}   = 1;
+    $build{resources}   = 1;
 }
 
 # do the work
@@ -156,21 +170,21 @@ $MOZ_SRC = cwd();
 
 if ($USE_TIMESTAMPED_LOGS)
 {
-	#Use time-stamped names so that you don't clobber your previous log file!
-	my $now = localtime();
-	while ($now =~ s@:@.@) {} # replace all colons by periods
-	my $logdir = ":Build Logs:";
-	if (!stat($logdir))
-	{
-	        print "Creating directory $logdir\n";
-	        mkdir $logdir, 0777 || die "Couldn't create directory $logdir";
-	}
-	OpenErrorLog("$logdir$now");
+    #Use time-stamped names so that you don't clobber your previous log file!
+    my $now = localtime();
+    while ($now =~ s@:@.@) {} # replace all colons by periods
+    my $logdir = ":Build Logs:";
+    if (!stat($logdir))
+    {
+            print "Creating directory $logdir\n";
+            mkdir $logdir, 0777 || die "Couldn't create directory $logdir";
+    }
+    OpenErrorLog("$logdir$now");
 }
 else
 {
-	OpenErrorLog("NGLayoutBuildLog");		# Release build
-	#OpenErrorLog("Mozilla.BuildLog");		# Tinderbox requires that name
+    OpenErrorLog("NGLayoutBuildLog");       # Release build
+    #OpenErrorLog("Mozilla.BuildLog");      # Tinderbox requires that name
 }
 
 Moz::StopForErrors();
diff --git a/mozilla/build/mac/MozJar.pm b/mozilla/build/mac/MozJar.pm
index 77531eca5e7..940bd9676f6 100644
--- a/mozilla/build/mac/MozJar.pm
+++ b/mozilla/build/mac/MozJar.pm
@@ -20,7 +20,7 @@ use Moz;
 use vars qw( @ISA @EXPORT );
 
 @ISA        = qw(Exporter);
-@EXPORT     = qw(CreateJarFileFromDirectory WriteOutJarFiles);
+@EXPORT     = qw(CreateJarFileFromDirectory WriteOutJarFiles SanityCheckJarOptions);
 
 
 #-------------------------------------------------------------------------------
@@ -98,6 +98,39 @@ sub CreateJarFileFromDirectory($$$)
     MacPerl::SetFileInfo("ZIP ", "ZIP ", $jarpath);
 }
 
+
+#-------------------------------------------------------------------------------
+# SanityCheckJarOptions
+# 
+#-------------------------------------------------------------------------------
+sub SanityCheckJarOptions()
+{
+    if (! $main::options{jar_manifests})
+    {
+        print "\$options{jar_manifests} is off, which means you are using obsolete MANIFEST files to install chrome resources.\n";
+        return;
+    }
+
+    if (!$main::options{chrome_jars} && !$main::options{chrome_files})
+    {
+        print "Both \$options{chrome_jars} and \$options{chrome_files} are off. You won't get any chrome.\n";
+        return;
+    }
+
+    if (!$main::options{chrome_jars} && $main::options{use_jars})
+    {
+        print "\$options{chrome_jars} is off but \$options{use_jars} is on. Your build won't run (expects jars, got files).\n";
+        return;
+    }
+
+    if (!$main::options{chrome_files} && !$main::options{use_jars})
+    {
+        print "\$options{chrome_jars} is off but \$options{chrome_files} is on. Your build won't run (expects files, got jars).\n";
+        return;
+    }
+}
+
+
 #-------------------------------------------------------------------------------
 # printZipContents
 # 
@@ -186,7 +219,7 @@ sub addToJarFile($$$$$$$)
         }
     }
     
-    if ($main::options{jars})
+    if ($main::options{chrome_jars})
     {
         my($zip) = $jars->{$jar_id};
         unless ($zip) { die "Can't find Zip entry for $jar_id\n"; }
@@ -276,7 +309,7 @@ sub setupJarFile($$$)
     $jar_file =~ s|/|:|g;           # slash to colons
     my($full_jar_path) = Moz::full_path_to($dest_path.":".$jar_file);
 
-    if ($main::options{jars})
+    if ($main::options{chrome_jars})
     {
         my($zip) = $jar_hash->{$jar_id};
         if (!$zip)      # if we haven't made it already, do so
@@ -318,7 +351,7 @@ sub closeJarFile($$)
 
     # print "Closing jar file $jar_path\n";
 
-    if ($main::options{jars})
+    if ($main::options{chrome_jars})
     {
     
     }
@@ -339,7 +372,7 @@ sub WriteOutJarFiles($$)
 {
     my($chrome_dir, $jars) = @_;
 
-    unless ($main::options{jars}) { return; }
+    unless ($main::options{chrome_jars}) { return; }
     
     my($full_chrome_path) = Moz::full_path_to($chrome_dir);
 
@@ -382,7 +415,7 @@ sub registerChromePackage($$$$$$)
     
     my($chrome_entry);
     
-    if ($main::options{jars}) {
+    if ($main::options{use_jars}) {
         $chrome_entry = "$chrome_type,install,url,jar:resource:/chrome/$manifest_subdir!/$chrome_type/$pkg_name";
     } else {
         $manifest_subdir =~ s/\.jar$/\//;
@@ -427,9 +460,10 @@ sub CreateJarFromManifest($$$)
 {
     my($jar_man_path, $dest_path, $jars) = @_;
     
-    if ($main::options{jars}) {
+    if ($main::options{chrome_jars}) {
         print "Jarring from $jar_man_path\n";
-    } else {
+    }
+    if ($main::options{chrome_files}) {
         print "Installing files from $jar_man_path\n";
     }
 
diff --git a/mozilla/build/mac/NGLayoutBuildList.pm b/mozilla/build/mac/NGLayoutBuildList.pm
index 81e25d7e9e4..eb841901c18 100644
--- a/mozilla/build/mac/NGLayoutBuildList.pm
+++ b/mozilla/build/mac/NGLayoutBuildList.pm
@@ -253,7 +253,7 @@ sub InstallManifestRDFFiles()
     my $chrome_subdir = "Chrome:";
     my $chrome_dir = "$dist_dir" . $chrome_subdir;
 
-    my($building_jars) = $main::options{jars};
+    my($building_jars) = 0;     # $main::options{chrome_jars};
 
     # nuke installed-chrome.txt
     unlink ${chrome_dir}."installed-chrome.txt";
@@ -337,6 +337,8 @@ sub ConfigureBuildSystem()
     # launch codewarrior and write idepath.txt
     LaunchCodeWarrior();
     
+    SanityCheckJarOptions();
+    
     #// For now, if we discover a newer header file than existed in Universal Interfaces 3.2,
     #// we'll assume that 3.3 or later is in use.
     my($universal_interfaces) = getCodeWarriorPath("MacOS Support:Universal:Interfaces:CIncludes:");
@@ -621,6 +623,8 @@ sub SetDefaultSkin($)
     my($dist_dir) = _getDistDirectory();
     my($chrome_subdir) = $dist_dir."Chrome";
     
+    print "Setting default skin to $skin\n";
+    
     open(CHROMEFILE, ">>${chrome_subdir}:installed-chrome.txt") || die "Failed to open installed_chrome.txt\n";
     print(CHROMEFILE "skin,install,select,$skin\n");
     close(CHROMEFILE);
@@ -1364,7 +1368,7 @@ sub ProcessJarManifests()
 
 sub BuildJarFiles()
 {
-    unless( $main::build{resources} && $main::options{jars} ) { return; }
+    unless( $main::build{resources} ) { return; }
     _assertRightDirectory();
 
     print("--- Starting JAR building ----\n");
diff --git a/mozilla/build/mac/PullNGlayout.pl b/mozilla/build/mac/PullNGlayout.pl
index 011bb8b801b..4702fab0e8b 100644
--- a/mozilla/build/mac/PullNGlayout.pl
+++ b/mozilla/build/mac/PullNGlayout.pl
@@ -36,10 +36,10 @@ $pull{runtime} = 0;
 
 if ($pull{all})
 {
-	foreach $k (keys(%pull))
-	{
-		$pull{$k} = 1;
-	}
+    foreach $k (keys(%pull))
+    {
+        $pull{$k} = 1;
+    }
 }
 
 # you should not have to edit anything bellow