getcwd.c (getcwd): If pathname is NULL, then obtain SIZE bytes of space using malloc.

P
        * getcwd.c (getcwd): If pathname is NULL, then obtain SIZE
        bytes of space using malloc.

From-SVN: r27161

libiberty/getcwd.c

@@ -14,6 +14,9 @@ DESCRIPTION
 	current directory's path doesn't fit in LEN characters, the result
 	is NULL and errno is set.
 
+	If pathname is a null pointer, getcwd() will obtain size bytes of
+	space using malloc.
+
 BUGS
 	Emulated via the getwd() call, which is reasonable for most
 	systems that do not have getcwd().
@@ -48,6 +51,13 @@ getcwd (buf, len)
       errno = ERANGE;
       return 0;
     }
+    if (!buf) {
+       buf = (char*)malloc(len);
+       if (!buf) {
+           errno = ENOMEM;
+	   return 0;
+       }
+    }
     strcpy (buf, ourbuf);
   }
   return buf;