u8-istream: Fix handling of partial reads.

[pspp] / src / libpspp / u8-istream.c

diff --git a/src/libpspp/u8-istream.c b/src/libpspp/u8-istream.c
index 2486ca1ada31c53966e556dfc9932f4ace47a3be..6347a6701a9b86c2147f5d86b3b9a82823045682 100644 (file)
--- a/src/libpspp/u8-istream.c
+++ b/src/libpspp/u8-istream.c
@@ -1,5 +1,5 @@
 /* PSPP - a program for statistical analysis.
-   Copyright (C) 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
+   Copyright (C) 2010, 2011, 2012, 2013, 2014 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -203,14 +203,22 @@ fill_buffer (struct u8_istream *is)
   is->head = is->buffer;
 
   /* Read more input. */
+  n = 0;
   do
     {
-      n = read (is->fd, is->buffer + is->length,
-                U8_ISTREAM_BUFFER_SIZE - is->length);
+      ssize_t retval = read (is->fd, is->buffer + is->length,
+                             U8_ISTREAM_BUFFER_SIZE - is->length);
+      if (retval > 0)
+        {
+          n += retval;
+          is->length += retval;
+        }
+      else if (retval == 0)
+        return n;
+      else if (errno != EINTR)
+        return n > 0 ? n : -1;
     }
-  while (n < 0 && errno == EINTR);
-  if (n > 0)
-    is->length += n;
+  while (is->length < U8_ISTREAM_BUFFER_SIZE);
   return n;
 }