[BZ #713]

2005-09-26  Ulrich Drepper  <drepper@redhat.com>
	[BZ #713]
	* libio/iofgets.c: Treat N==1 correctly.
	* libio/iofgets_u.c: Likewise.
	* libio/iofgetws.c: Likewise.
	* libio/iofgetws_u.c: Likewise.
	* stdio-common/Makefile (tests): Add tst-fgets.
	* stdio-common/tst-fgets.c: New file.

diff --git a/ChangeLog b/ChangeLog
index 935693f..bafd427 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2005-09-26  Ulrich Drepper  <drepper@redhat.com>
+
+       [BZ #713]
+       * libio/iofgets.c: Treat N==1 correctly.
+       * libio/iofgets_u.c: Likewise.
+       * libio/iofgetws.c: Likewise.
+       * libio/iofgetws_u.c: Likewise.
+       * stdio-common/Makefile (tests): Add tst-fgets.
+       * stdio-common/tst-fgets.c: New file.
+
 2005-01-11  Thorsten Kukuk  <kukuk@suse.de>
 
        [BZ #652]

diff --git a/libio/iofgets.c b/libio/iofgets.c
index 879cc97..601b174 100644 (file)
--- a/libio/iofgets.c
+++ b/libio/iofgets.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1993, 1995, 1996, 1997, 1998, 1999, 2002, 2003
+/* Copyright (C) 1993, 1995, 1996, 1997, 1998, 1999, 2002, 2003, 2005
    Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -41,6 +41,14 @@ _IO_fgets (buf, n, fp)
   CHECK_FILE (fp, NULL);
   if (n <= 0)
     return NULL;
+  if (__builtin_expect (n == 1, 0))
+    {
+      /* Another irregular case: since we have to store a NUL byte and
+        there is only room for exactly one byte, we don't have to
+        read anything.  */
+      buf[0] = '\0';
+      return buf;
+    }
   _IO_acquire_lock (fp);
   /* This is very tricky since a file descriptor may be in the
      non-blocking mode. The error flag doesn't mean much in this

diff --git a/libio/iofgets_u.c b/libio/iofgets_u.c
index ded2a7c..4fb5b1c 100644 (file)
--- a/libio/iofgets_u.c
+++ b/libio/iofgets_u.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1993,1995,1996,1997,1998,2002 Free Software Foundation, Inc.
+/* Copyright (C) 1993,1995-1998,2002,2005 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -40,6 +40,14 @@ fgets_unlocked (buf, n, fp)
   CHECK_FILE (fp, NULL);
   if (n <= 0)
     return NULL;
+  if (__builtin_expect (n == 1, 0))
+    {
+      /* Another irregular case: since we have to store a NUL byte and
+        there is only room for exactly one byte, we don't have to
+        read anything.  */
+      buf[0] = '\0';
+      return buf;
+    }
   /* This is very tricky since a file descriptor may be in the
      non-blocking mode. The error flag doesn't mean much in this
      case. We return an error only when there is a new error. */

diff --git a/libio/iofgetws.c b/libio/iofgetws.c
index 654c051..7753911 100644 (file)
--- a/libio/iofgetws.c
+++ b/libio/iofgetws.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1993, 1995, 1996, 1997, 1998, 1999, 2001
+/* Copyright (C) 1993, 1995, 1996, 1997, 1998, 1999, 2001, 2005
    Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -41,6 +41,14 @@ fgetws (buf, n, fp)
   CHECK_FILE (fp, NULL);
   if (n <= 0)
     return NULL;
+  if (__builtin_expect (n == 1, 0))
+    {
+      /* Another irregular case: since we have to store a NUL byte and
+        there is only room for exactly one byte, we don't have to
+        read anything.  */
+      buf[0] = L'\0';
+      return buf;
+    }
   _IO_acquire_lock (fp);
   /* This is very tricky since a file descriptor may be in the
      non-blocking mode. The error flag doesn't mean much in this

diff --git a/libio/iofgetws_u.c b/libio/iofgetws_u.c
index 1253564..9fb8a5c 100644 (file)
--- a/libio/iofgetws_u.c
+++ b/libio/iofgetws_u.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1993, 95, 96, 97, 98, 99 Free Software Foundation, Inc.
+/* Copyright (C) 1993, 95, 96, 97, 98, 99, 2005 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -40,6 +40,14 @@ fgetws_unlocked (buf, n, fp)
   CHECK_FILE (fp, NULL);
   if (n <= 0)
     return NULL;
+  if (__builtin_expect (n == 1, 0))
+    {
+      /* Another irregular case: since we have to store a NUL byte and
+        there is only room for exactly one byte, we don't have to
+        read anything.  */
+      buf[0] = L'\0';
+      return buf;
+    }
   /* This is very tricky since a file descriptor may be in the
      non-blocking mode. The error flag doesn't mean much in this
      case. We return an error only when there is a new error. */

diff --git a/libio/iogetline.c b/libio/iogetline.c
index eca38cf..022a444 100644 (file)
--- a/libio/iogetline.c
+++ b/libio/iogetline.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 1993,1997,1998,2000,2001,2002 Free Software Foundation, Inc.
+/* Copyright (C) 1993,1997,1998,2000,2001,2002,2005
+   Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -73,7 +74,8 @@ _IO_getline_info (fp, buf, n, delim, extract_delim, eof)
          int c = __uflow (fp);
          if (c == EOF)
            {
-             if (eof) *eof = c;
+             if (eof)
+               *eof = c;
              break;
            }
          if (c == delim)
@@ -89,31 +91,31 @@ _IO_getline_info (fp, buf, n, delim, extract_delim, eof)
          *ptr++ = c;
          n--;
        }
-       else
-         {
-           char *t;
-           if ((_IO_size_t) len >= n)
-             len = n;
-           t = (char *) memchr ((void *) fp->_IO_read_ptr, delim, len);
-           if (t != NULL)
-             {
-               _IO_size_t old_len = ptr-buf;
-               len = t - fp->_IO_read_ptr;
-               if (extract_delim >= 0)
-                 {
-                   ++t;
-                   if (extract_delim > 0)
-                     ++len;
-                 }
-               memcpy ((void *) ptr, (void *) fp->_IO_read_ptr, len);
-               fp->_IO_read_ptr = t;
-               return old_len + len;
-             }
-           memcpy ((void *) ptr, (void *) fp->_IO_read_ptr, len);
-           fp->_IO_read_ptr += len;
-           ptr += len;
-           n -= len;
-         }
+      else
+       {
+         char *t;
+         if ((_IO_size_t) len >= n)
+           len = n;
+         t = (char *) memchr ((void *) fp->_IO_read_ptr, delim, len);
+         if (t != NULL)
+           {
+             _IO_size_t old_len = ptr-buf;
+             len = t - fp->_IO_read_ptr;
+             if (extract_delim >= 0)
+               {
+                 ++t;
+                 if (extract_delim > 0)
+                   ++len;
+               }
+             memcpy ((void *) ptr, (void *) fp->_IO_read_ptr, len);
+             fp->_IO_read_ptr = t;
+             return old_len + len;
+           }
+         memcpy ((void *) ptr, (void *) fp->_IO_read_ptr, len);
+         fp->_IO_read_ptr += len;
+         ptr += len;
+         n -= len;
+       }
     }
   return ptr - buf;
 }

diff --git a/stdio-common/Makefile b/stdio-common/Makefile
index 39c7d9d..dbf7d16 100644 (file)
--- a/stdio-common/Makefile
+++ b/stdio-common/Makefile
@@ -53,7 +53,7 @@ tests := tstscanf test_rdwr test-popen tstgetln test-fseek \
         scanf11 scanf12 tst-tmpnam tst-cookie tst-obprintf tst-sscanf \
         tst-swprintf tst-fseek tst-fmemopen test-vfprintf tst-gets \
         tst-perror tst-sprintf tst-rndseek tst-fdopen tst-fphex bug14 bug15 \
-        tst-popen tst-unlockedio tst-fmemopen2 tst-put-error
+        tst-popen tst-unlockedio tst-fmemopen2 tst-put-error tst-fgets
 
 test-srcs = tst-unbputc tst-printf
 

diff --git a/stdio-common/tst-fgets.c b/stdio-common/tst-fgets.c
new file mode 100644 (file)
index 0000000..b8e205c
--- /dev/null
+++ b/stdio-common/tst-fgets.c
@@ -0,0 +1,20 @@
+/* Derived from the test case in
+   http://sourceware.org/bugzilla/show_bug.cgi?id=713.  */
+#include <stdio.h>
+
+static int
+do_test (void)
+{
+  FILE *fp = fmemopen ("hello", 5, "r");
+  char buf[2];
+  char *bp = fgets (buf, sizeof (buf), fp);
+  printf ("fgets: %s\n", bp == buf ? "OK" : "ERROR");
+  int res = bp != buf;
+  bp = fgets_unlocked (buf, sizeof (buf), fp);
+  printf ("fgets_unlocked: %s\n", bp == buf ? "OK" : "ERROR");
+  res |= bp != buf;
+  return res;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"