Merge changes between r25087 and r25236 from /fsf/trunk.HEADmaster

git-svn-id: svn://svn.eglibc.org/trunk@25237 7b3dc134-2b1b-0410-93df-9e9f96275f8d

3 files changed, 115 insertions, 5 deletions

diff --git a/libc/libio/Makefile b/libc/libio/Makefile
index b2aa50f0d..7c8036207 100644
--- a/libc/libio/Makefile
+++ b/libc/libio/Makefile
@@ -78,7 +78,7 @@ tests-$(OPTION_POSIX_WIDE_CHAR_DEVICE_IO)		\
 	bug-wfflush bug-wmemstream1 tst-fopenloc2	\
 	tst_getwc					\
 	tst_putwc tst_wprintf tst_wprintf2 tst_wscanf	\
-	tst-fgetwc bug-wsetpos tst-fseek
+	tst-fgetwc bug-wsetpos tst-fseek tst-ftell-partial-wide
 tests-$(OPTION_POSIX_C_LANG_WIDE_CHAR)			\
      += tst_swprintf tst_swscanf			\
 	tst-sscanf					\
diff --git a/libc/libio/tst-ftell-partial-wide.c b/libc/libio/tst-ftell-partial-wide.c
new file mode 100644
index 000000000..3734e774a
--- /dev/null
+++ b/libc/libio/tst-ftell-partial-wide.c
@@ -0,0 +1,107 @@
+/* Verify that ftell does not go into an infinite loop when a conversion fails
+   due to insufficient space in the buffer.
+   Copyright (C) 2014 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <wchar.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <locale.h>
+#include <errno.h>
+#include <unistd.h>
+
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
+
+/* Arbitrary number large enough so that the target buffer during conversion is
+   not large enough.  */
+#define STRING_SIZE (1400)
+#define NSTRINGS (2)
+
+static int
+do_test (void)
+{
+  FILE *fp = NULL;
+  wchar_t *inputs[NSTRINGS] = {NULL};
+  int ret = 1;
+
+  if (setlocale (LC_ALL, "en_US.UTF-8") == NULL)
+    {
+      printf ("Cannot set en_US.UTF-8 locale.\n");
+      goto out;
+    }
+
+
+  /* Generate input from one character, chosen because it has an odd number of
+     bytes in UTF-8, making it easier to reproduce the problem:
+
+     NAME    Hiragana letter GO
+     CHAR    ご
+     UTF-8   E38194
+     UCS     3054
+     MARC-8  692434  */
+  wchar_t seed = L'ご';
+  for (int i = 0; i < NSTRINGS; i++)
+    {
+      inputs[i] = malloc (STRING_SIZE * sizeof (wchar_t));
+      if (inputs[i] == NULL)
+	{
+	  printf ("Failed to allocate memory for inputs: %m\n");
+	  goto out;
+	}
+      wmemset (inputs[i], seed, STRING_SIZE - 1);
+      inputs[i][STRING_SIZE - 1] = L'\0';
+    }
+
+  char *filename;
+  int fd = create_temp_file ("tst-fseek-wide-partial.out", &filename);
+
+  if (fd == -1)
+    {
+      printf ("create_temp_file: %m\n");
+      goto out;
+    }
+
+  fp = fdopen (fd, "w+");
+  if (fp == NULL)
+    {
+      printf ("fopen: %m\n");
+      close (fd);
+      goto out;
+    }
+
+  for (int i = 0; i < NSTRINGS; i++)
+    {
+      printf ("offset: %ld\n", ftell (fp));
+      if (fputws (inputs[i], fp) == -1)
+	{
+	  perror ("fputws");
+	  goto out;
+	}
+    }
+  ret = 0;
+
+out:
+  if (fp != NULL)
+    fclose (fp);
+  for (int i = 0; i < NSTRINGS; i++)
+    free (inputs[i]);
+
+  return ret;
+}
diff --git a/libc/libio/wfileops.c b/libc/libio/wfileops.c
index 87d3cdcf3..877fc1f82 100644
--- a/libc/libio/wfileops.c
+++ b/libc/libio/wfileops.c
@@ -715,7 +715,7 @@ _IO_wfile_seekoff (fp, offset, dir, mode)
 		       - fp->_wide_data->_IO_write_base) / clen;
 	  else
 	    {
-	      enum __codecvt_result status;
+	      enum __codecvt_result status = __codecvt_ok;
 	      delta = (fp->_wide_data->_IO_write_ptr
 		       - fp->_wide_data->_IO_write_base);
 	      const wchar_t *write_base = fp->_wide_data->_IO_write_base;
@@ -728,9 +728,12 @@ _IO_wfile_seekoff (fp, offset, dir, mode)
 		 flush buffers for every ftell.  */
 	      do
 		{
-		  /* Ugh, no point trying to avoid the flush.  Just do it
-		     and go back to how it was with the read mode.  */
-		  if (delta > 0 && new_write_ptr == fp->_IO_buf_end)
+		  /* There is not enough space in the buffer to do the entire
+		     conversion, so there is no point trying to avoid the
+		     buffer flush.  Just do it and go back to how it was with
+		     the read mode.  */
+		  if (status == __codecvt_partial
+		      || (delta > 0 && new_write_ptr == fp->_IO_buf_end))
 		    {
 		      if (_IO_switch_to_wget_mode (fp))
 			return WEOF;