X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fxgetcwd.c;h=1409bcfba7d684d628e6b1283a2e7303f1d6dd4e;hb=7d8d614280a61d7bbdac8e218bfdc1aa849329c7;hp=95d0ab96cdf05ff0e608fdeb8eee34bdbe6734ee;hpb=9024bca255ea4e2a083fbe0963155f6b3002fa45;p=gnulib.git

diff --git a/lib/xgetcwd.c b/lib/xgetcwd.c
index 95d0ab96c..1409bcfba 100644
--- a/lib/xgetcwd.c
+++ b/lib/xgetcwd.c
@@ -28,18 +28,24 @@ extern int errno;
 #endif
 
 #include <sys/types.h>
-#include "pathmax.h"
+
+#if HAVE_STDLIB_H
+# include <stdlib.h>
+#endif
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#endif
 
 #if HAVE_GETCWD
 char *getcwd ();
 #else
+# include "pathmax.h"
+# define INITIAL_BUFFER_SIZE (PATH_MAX + 1)
 char *getwd ();
 # define getcwd(Buf, Max) getwd (Buf)
 #endif
 
-extern void *xmalloc ();
-extern char *xstrdup ();
-extern void free ();
+#include "xalloc.h"
 
 /* Return the current directory, newly allocated, arbitrarily long.
    Return NULL and set errno on error. */
@@ -47,43 +53,35 @@ extern void free ();
 char *
 xgetcwd ()
 {
-#if defined __GLIBC__ && __GLIBC__ >= 2
-  return getcwd (NULL, 0);
+#if HAVE_GETCWD_NULL
+  char *cwd = getcwd (NULL, 0);
+  if (! cwd && errno == ENOMEM)
+    xalloc_die ();
+  return cwd;
 #else
-  char *ret;
-  unsigned path_max;
-  char buf[1024];
 
-  errno = 0;
-  ret = getcwd (buf, sizeof (buf));
-  if (ret != NULL)
-    return xstrdup (buf);
-  if (errno != ERANGE)
-    return NULL;
+  /* The initial buffer size for the working directory.  A power of 2
+     detects arithmetic overflow earlier, but is not required.  */
+# ifndef INITIAL_BUFFER_SIZE
+#  define INITIAL_BUFFER_SIZE 128
+# endif
 
-  path_max = 1300;
-  path_max += 2;		/* The getcwd docs say to do this. */
+  size_t buf_size = INITIAL_BUFFER_SIZE;
 
-  for (;;)
+  while (1)
     {
-      char *cwd = (char *) xmalloc (path_max);
-
-      errno = 0;
-      ret = getcwd (cwd, path_max);
-      if (ret != NULL)
-	return ret;
-      if (errno != ERANGE)
-	{
-	  int save_errno = errno;
-	  free (cwd);
-	  errno = save_errno;
-	  return NULL;
-	}
-
-      free (cwd);
-
-      path_max += path_max / 16;
-      path_max += 32;
+      char *buf = xmalloc (buf_size);
+      char *cwd = getcwd (buf, buf_size);
+      int saved_errno;
+      if (cwd)
+	return cwd;
+      saved_errno = errno;
+      free (buf);
+      if (saved_errno != ERANGE)
+	return NULL;
+      buf_size *= 2;
+      if (buf_size == 0)
+	xalloc_die ();
     }
 #endif
 }