[BZ #1078]

2005-09-27  Ulrich Drepper  <drepper@redhat.com>
	[BZ #1078]
	* libio/fileops.c (_IO_new_file_xsputn): Determine amount of
	available space in non-line-buffered buffer correctly.
	* libio/oldfileops.c (_IO_old_file_xsputn): Likewise.
	* stdio-common/Makefile (tests): Add tst-fwrite.
	* stdio-common/tst-fwrite.c: New file.

ChangeLog

@@ -1,3 +1,12 @@
+2005-09-27  Ulrich Drepper  <drepper@redhat.com>
+
+	[BZ #1078]
+	* libio/fileops.c (_IO_new_file_xsputn): Determine amount of
+	available space in non-line-buffered buffer correctly.
+	* libio/oldfileops.c (_IO_old_file_xsputn): Likewise.
+	* stdio-common/Makefile (tests): Add tst-fwrite.
+	* stdio-common/tst-fwrite.c: New file.
+
 2005-09-26  Ulrich Drepper  <drepper@redhat.com>
 
 	[BZ #838]

libio/fileops.c

@@ -1281,7 +1281,7 @@ _IO_new_file_xsputn (f, data, n)
   register const char *s = (const char *) data;
   _IO_size_t to_do = n;
   int must_flush = 0;
-  _IO_size_t count;
+  _IO_size_t count = 0;
 
   if (n <= 0)
     return 0;
@@ -1290,7 +1290,6 @@ _IO_new_file_xsputn (f, data, n)
      (or the filebuf is unbuffered), use sys_write directly. */
 
   /* First figure out how much space is available in the buffer. */
-  count = f->_IO_write_end - f->_IO_write_ptr; /* Space available. */
   if ((f->_flags & _IO_LINE_BUF) && (f->_flags & _IO_CURRENTLY_PUTTING))
     {
       count = f->_IO_buf_end - f->_IO_write_ptr;
@@ -1308,6 +1307,9 @@ _IO_new_file_xsputn (f, data, n)
 	    }
 	}
     }
+  else if (f->_IO_write_end > f->_IO_write_ptr)
+    count = f->_IO_write_end - f->_IO_write_ptr; /* Space available. */
+
   /* Then fill the buffer. */
   if (count > 0)
     {

libio/oldfileops.c

@@ -695,7 +695,7 @@ _IO_old_file_xsputn (f, data, n)
   register const char *s = (char *) data;
   _IO_size_t to_do = n;
   int must_flush = 0;
-  _IO_size_t count;
+  _IO_size_t count = 0;
 
   if (n <= 0)
     return 0;
@@ -704,7 +704,6 @@ _IO_old_file_xsputn (f, data, n)
      (or the filebuf is unbuffered), use sys_write directly. */
 
   /* First figure out how much space is available in the buffer. */
-  count = f->_IO_write_end - f->_IO_write_ptr; /* Space available. */
   if ((f->_flags & _IO_LINE_BUF) && (f->_flags & _IO_CURRENTLY_PUTTING))
     {
       count = f->_IO_buf_end - f->_IO_write_ptr;
@@ -722,6 +721,9 @@ _IO_old_file_xsputn (f, data, n)
 	    }
 	}
     }
+  else if (f->_IO_write_end > f->_IO_write_ptr)
+    count = f->_IO_write_end - f->_IO_write_ptr; /* Space available. */
+
   /* Then fill the buffer. */
   if (count > 0)
     {

stdio-common/Makefile

@@ -53,7 +53,8 @@ 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-fgets
+	 tst-popen tst-unlockedio tst-fmemopen2 tst-put-error tst-fgets \
+	 tst-fwrite
 
 test-srcs = tst-unbputc tst-printf
 

stdio-common/tst-fwrite.c

@@ -0,0 +1,70 @@
+/* Derived from the test case in
+   http://sourceware.org/bugzilla/show_bug.cgi?id=1078.  */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#define OUT_SIZE 10000
+
+
+static int fd;
+
+static void prepare (void);
+#define PREPARE(argc, argv) prepare ()
+
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+
+#include "../test-skeleton.c"
+
+
+static void
+prepare (void)
+{
+  fd = create_temp_file ("tst-fwrite.", NULL);
+  if (fd == -1)
+    {
+      puts ("cannot create temporary file");
+      exit (1);
+    }
+}
+
+
+static int
+do_test (void)
+{
+  FILE* f = fdopen (fd, "w+");
+  if (f == NULL) {
+    puts ("cannot create stream");
+    return 1;
+  }
+  puts ("Opened temp file");
+
+  if (fwrite ("a", 1, 1, f) != 1)
+    {
+      puts ("1st fwrite failed");
+      return 1;
+    }
+  puts ("Wrote a byte");
+  fflush (f);
+
+  char buffer[10000];
+  size_t i = fread (buffer, 1, sizeof (buffer), f);
+  printf ("Read %zu bytes\n", i);
+
+  for (i = 0; i < OUT_SIZE; i++)
+    {
+      if (fwrite ("n", 1, 1, f) != 1)
+	{
+	  printf ("fwrite in loop round %zu failed\n", i);
+	  return 1;
+	}
+
+      if ((i + 1) % 1000 == 0)
+	printf ("wrote %zu bytes ...\n", i + 1);
+    }
+
+  printf ("Wrote %i bytes [done]\n", OUT_SIZE);
+
+  return 0;
+}