--- src/output.c.orig	2006-05-14 13:40:35.000000000 -0700
+++ src/output.c	2007-09-26 01:40:58.000000000 -0700
@@ -40,6 +40,10 @@
 #include "symtab.h"
 #include "tables.h"
 
+/* these are for _makerelative() */
+#include <mach-o/dyld.h>
+#include <sys/param.h>
+#include <stdlib.h>
 
 static struct obstack format_obstack;
 
@@ -107,6 +111,49 @@
 GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_item_number_table, item_number)
 GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_state_number_table, state_number)
 
+/* see 5090475 & 5460821 */
+static char	_m4[PATH_MAX];
+static char	_pkgdatadir[PATH_MAX];
+
+static void
+_makerelative(void)
+{
+    char	buf[PATH_MAX];
+    uint32_t	bufsize = sizeof(buf);
+    char 	*cp;
+
+    if (*_pkgdatadir)
+	return;
+
+    if (_NSGetExecutablePath(buf, &bufsize) != 0)
+	goto error;
+
+    cp = buf + strlen(buf);
+    while(cp > buf && *--cp != '/') {} // skip over progname
+    if(cp <= buf)
+	goto error;
+    *cp = 0;
+
+    if(realpath(buf, _pkgdatadir) == NULL)
+	goto error;
+
+    /* copy the bin directory to _m4, and append base of M4 */
+    strcpy(_m4, _pkgdatadir);
+    strlcat(_m4, "/", sizeof(_m4));
+    strlcat(_m4, base_name(M4), sizeof(_m4));
+
+    cp = _pkgdatadir + strlen(_pkgdatadir);
+    while(cp > _pkgdatadir && *--cp != '/') {} // skip over dir (usually "bin")
+    if(cp <= _pkgdatadir)
+	goto error;
+    *cp = 0;
+    strlcat(_pkgdatadir, "/share/bison", sizeof(_pkgdatadir));
+    return;
+
+error:
+    strlcpy(_pkgdatadir, PKGDATADIR, sizeof(_pkgdatadir));
+    strlcpy(_m4, M4, sizeof(_m4));
+}
 
 /*--------------------------------------------------------------------.
 | Print to OUT a representation of STRING escaped both for C and M4.  |
@@ -512,10 +559,15 @@
   char *full_m4sugar;
   char *full_skeleton;
   char const *p;
-  char const *m4 = (p = getenv ("M4")) ? p : M4;
-  char const *pkgdatadir = (p = getenv ("BISON_PKGDATADIR")) ? p : PKGDATADIR;
+  char const *m4;
+  char const *pkgdatadir;
   size_t skeleton_size = strlen (skeleton) + 1;
-  size_t pkgdatadirlen = strlen (pkgdatadir);
+  size_t pkgdatadirlen;
+
+  _makerelative();
+  m4 = (p = getenv ("M4")) ? p : _m4;
+  pkgdatadir = (p = getenv ("BISON_PKGDATADIR")) ? p : _pkgdatadir;
+  pkgdatadirlen = strlen (pkgdatadir);
   while (pkgdatadirlen && pkgdatadir[pkgdatadirlen - 1] == '/')
     pkgdatadirlen--;
   full_skeleton = xmalloc (pkgdatadirlen + 1
@@ -621,7 +673,8 @@
   /* About the skeletons. */
   {
     char const *pkgdatadir = getenv ("BISON_PKGDATADIR");
-    MUSCLE_INSERT_STRING ("pkgdatadir", pkgdatadir ? pkgdatadir : PKGDATADIR);
+    _makerelative();
+    MUSCLE_INSERT_STRING ("pkgdatadir", pkgdatadir ? pkgdatadir : _pkgdatadir);
     MUSCLE_INSERT_C_STRING ("skeleton", skeleton);
   }
 }