X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fxreadlink.c;h=0f5e7d26f2fcd7d27ff462160e0437592d4cf6db;hb=76bd5cd5304484617bd8b15bfc8a59b0264482b8;hp=2e66c07f240791c8c1b05609da58ca58e6dd3b34;hpb=a62be9f4039b4499cfbb76e394cad2259d03fa84;p=gnulib.git

diff --git a/lib/xreadlink.c b/lib/xreadlink.c
index 2e66c07f2..0f5e7d26f 100644
--- a/lib/xreadlink.c
+++ b/lib/xreadlink.c
@@ -41,6 +41,8 @@
 # define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2))
 #endif
 
+#define MAXSIZE (SIZE_MAX < SSIZE_MAX ? SIZE_MAX : SSIZE_MAX)
+
 #include "xalloc.h"
 
 /* Call readlink to get the symbolic link value of FILENAME.
@@ -56,14 +58,17 @@ xreadlink (char const *filename, size_t size)
 {
   /* The initial buffer size for the link value.  A power of 2
      detects arithmetic overflow earlier, but is not required.  */
-  size_t buf_size = size + 1;
+  size_t buf_size = size < MAXSIZE ? size + 1 : MAXSIZE;
 
   while (1)
     {
       char *buffer = xmalloc (buf_size);
-      ssize_t link_length = readlink (filename, buffer, buf_size);
+      ssize_t r = readlink (filename, buffer, buf_size);
+      size_t link_length = r;
 
-      if (link_length < 0)
+      /* On AIX 5L v5.3 and HP-UX 11i v2 04/09, readlink returns -1
+	 with errno == ERANGE if the buffer is too small.  */
+      if (r < 0 && errno != ERANGE)
 	{
 	  int saved_errno = errno;
 	  free (buffer);
@@ -71,15 +76,18 @@ xreadlink (char const *filename, size_t size)
 	  return NULL;
 	}
 
-      if ((size_t) link_length < buf_size)
+      if (link_length < buf_size)
 	{
 	  buffer[link_length] = 0;
 	  return buffer;
 	}
 
       free (buffer);
-      buf_size *= 2;
-      if (! (0 < buf_size && buf_size <= SSIZE_MAX))
+      if (buf_size <= MAXSIZE / 2)
+	buf_size *= 2;
+      else if (buf_size < MAXSIZE)
+	buf_size = MAXSIZE;
+      else
 	xalloc_die ();
     }
 }