relocatable: Fix that /@unixroot prefix is not working on OS/2 kLIBC

OS/2 kLIBC has a feature to rewrite some path components. For example,
'/@unixroot' is replaced with a value of $UNIXROOT if it is.

So prepending a drive letter to the path starting with '/' makes the
path starting with '/@unixroot' to 'x:/@unixroot' which is unexpected.

This will breaks the behavior of some programs depending on /@unixroot
prefix.

* lib/relocatable.c (relocate): Do not touch pathname if it is started
with '/@unixroot'.

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/relocatable.c b/lib/relocatable.c
index 60cb54ac7e..401f3e0e45 100644
--- a/lib/relocatable.c
+++ b/lib/relocatable.c
@@ -539,6 +539,18 @@ relocate (const char *pathname)
     }
 
 #ifdef __EMX__
+# ifdef __KLIBC__
+#  undef strncmp
+
+  if (pathname && strncmp (pathname, "/@unixroot", 10) == 0
+      && (pathname[10] == '\0' || pathname[10] == '/' || pathname[10] == '\\'))
+    {
+      /* kLIBC itself processes /@unixroot prefix */
+
+      return pathname;
+    }
+  else
+# endif
   if (pathname && ISSLASH (pathname[0]))
     {
       const char *unixroot = getenv ("UNIXROOT");