--- patch-2.5.9/pch.c	2003-05-20 15:03:17.000000000 +0100
+++ patch-2.5.9-mod/pch.c	2009-06-01 12:10:26.746207000 +0100
@@ -499,9 +499,18 @@
 	  (strnEQ(s, "< ", 2) || strnEQ(s, "> ", 2)) ) {
 	    p_start = previous_line;
 	    p_sline = p_input_line - 1;
-	    p_indent = indent;
 	    p_strip_trailing_cr = strip_trailing_cr;
 	    retval = NORMAL_DIFF;
+
+            if (p_indent > 0 && p_indent != indent)
+              {
+                retval = NO_DIFF; /* inconsistent indentation */
+              }
+            else
+              {
+                p_indent = indent;
+                retval = NORMAL_DIFF;
+              }
 	    goto scan_exit;
 	}
     }