Date: Thu, 19 Jun 1997 15:32:05 +0200 (METDST)
From: Robert Hoehne <robert DOT hoehne AT mathematik DOT tu-chemnitz DOT de>
To: DJGPP workers <djgpp-workers AT delorie DOT com>
Subject: symlink patch (6/6)
Message-Id: <Pine.HPP.3.95q.970619153143.4123J-100000@newton.mathematik.tu-chemnitz.de>
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Precedence: bulk

--- src/libc/posix/unistd/symlink.c~	Thu Sep 19 22:40:46 1996
+++ src/libc/posix/unistd/symlink.c	Wed Jun 18 16:33:56 1997
@@ -1,5 +1,6 @@
 #include <libc/stubs.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <errno.h>
 #include <fcntl.h>
@@ -29,6 +30,31 @@
   return p;
 }
 
+/*
+   This returns
+              -1, when the file does not exist
+               0, when it is not a v2 executable
+               1, when it is a v2 executable
+*/
+
+static int is_v2_prog(const char *program)
+{
+  const _v2_prog_type *type;
+
+  type = _check_v2_prog (program, -1);
+
+  if (!type->valid)
+    return -1;
+
+  if (type->object_format != _V2_OBJECT_FORMAT_COFF)
+    return 0;
+
+  if (type->version.v.major < 2)
+    return 0;
+
+  return 1;
+}
+
 /* Support the DJGPP ``symlinks'' for .exe files.  */
 int
 symlink (const char *source, const char *dest)
@@ -38,6 +64,8 @@
   char *np, ropt[FILENAME_MAX+15]; /* some extra for ``runfile='' */
   const char *src_base, *dest_base;
 
+  int v2_prog = 0;
+
   _fixpath (source, src_abs);
   _fixpath (dest, dest_abs);
   src_base = tail (src_abs);
@@ -54,11 +82,38 @@
   if (stricmp (src_abs, dest_abs) == 0)
     return 0;
 
+  /* Check at first, if the given name is a v2 executable (may be
+     unstubbed COFF image) */
+  v2_prog = is_v2_prog(src_abs);
+
+  /* It is an existing file but no v2 executable */
+  if (v2_prog == 0)
+  {
+    errno = EXDEV;
+    return -1;
+  }
+
   /* Allow to say `ln -s src dest' when we really
      mean `src.exe' and `dest.exe'  */
   np = src_abs + strlen (src_abs) - 4;
   if (stricmp (np, EXE_SUFFIX))
+  {
     strcat (src_abs, EXE_SUFFIX);
+    /* Now test again for v2 executable, but only if not already
+       succeed. */
+    v2_prog = v2_prog == 1 ? v2_prog : is_v2_prog(src_abs);
+  }
+
+  /* It is an existing file but no v2 executable */
+  if (v2_prog == 0)
+  {
+    errno = EXDEV;
+    return -1;
+  }
+
+  /* When we are here, either the file exists and is a v2 executable
+     or it does not exist and we hope, the the user knows what he
+     does. */
 
   /* Under LFN, we need the short version of the program name, since that
      is what the stub stores (and what a program gets in its argv[0]).  */