(file_name_completion): Install case-preserving changes from Emacs 18

[gnu-emacs] / src / lisp.h

diff --git a/src/lisp.h b/src/lisp.h
index c34dc54d7bcae9da9d418724a50ac11ac869d168..c6816f2cd5e2d0ebe3586adb0f3ae690a3c99377 100644 (file)
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -447,8 +447,18 @@ struct interval
   unsigned int position;       /* Cache of interval's character position  */
   struct interval *left;       /* Intervals which precede me. */
   struct interval *right;      /* Intervals which succeed me. */
-  struct interval *parent;     /* Parent in the tree, or the Lisp_Object
-                                  containing this interval tree. */
+
+  /* Parent in the tree, or the Lisp_Object containing this interval tree.
+
+     The mark bit on the root interval of an interval tree says
+     whether we have started (and possibly finished) marking the
+     tree.  If GC comes across an interval tree whose root's parent
+     field has its markbit set, it leaves the tree alone.
+
+     You'd think we could store this information in the parent object
+     somewhere (after all, that should be visited once and then
+     ignored too, right?), but strings are GC'd strangely.  */
+  struct interval *parent;
 
   /* The remaining components are `properties' of the interval.
      The first four are duplicates for things which can be on the list,
@@ -460,7 +470,11 @@ struct interval
                                       before this interval goes into it. */
   unsigned char rear_sticky;       /* Likewise for just after it. */
 
-  Lisp_Object plist;               /* Properties of this interval. */
+  /* Properties of this interval.
+     The mark bit on this field says whether this particular interval
+     tree node has been visited.  Since intervals should never be
+     shared, GC aborts if it seems to have visited an interval twice.  */
+  Lisp_Object plist;
 };
 
 typedef struct interval *INTERVAL;
@@ -1257,7 +1271,7 @@ extern Lisp_Object Frubber_band_rectangle ();
 
 /* defined in emacs.c */
 extern Lisp_Object decode_env_path ();
-extern Lisp_Object Vinvocation_name;
+extern Lisp_Object Vinvocation_name, Vinvocation_directory;
 void shut_down_emacs ( /* int signal, int no_x, Lisp_Object stuff */ );
 /* Nonzero means don't do interactive redisplay and don't change tty modes */
 extern int noninteractive;