autogen.sh: better error message when src_path contains spaces

Change-Id: I921ffaf2ee4be73ecfffca8bc36cfae484b70a32

Makefile.in

@@ -45,6 +45,7 @@ $(BUILDDIR)/config_host.mk : $(wildcard \
 		$(SRCDIR)/android/experimental/LOAndroid3/AndroidManifest.xml.in \
 		$(BUILDDIR)/autogen.input \
 		$(BUILDDIR)/autogen.lastrun \
+		$(BUILDDIR)/autogen.sh \
 		)
 	sh -c $(SRCDIR)/autogen.sh
 

autogen.sh

@@ -116,6 +116,9 @@ sub invalid_distro($$)
     closedir ($dirh);
 }
 
+# Avoid confusing "aclocal: error: non-option arguments are not accepted: '.../m4'." error message.
+die "\$src_path must not contain spaces, but it is '$src_path'." if ($src_path =~ / /);
+
 # Alloc $ACLOCAL to specify which aclocal to use
 $aclocal = $ENV{ACLOCAL} ? $ENV{ACLOCAL} : 'aclocal';