Update.

2002-02-25  Jakub Jelinek  <jakub@redhat.com>

	* libio/iofopen.c (__fopen_maybe_mmap): Set the initial
	position to fp->_offset if it is set.
	* stdio-common/Makefile (tests): Add tst-fdopen.
	* stdio-common/tst-fdopen.c: New test.

2002-02-25  Jakub Jelinek  <jakub@redhat.com>

	* libio/fileops.c (_IO_file_xsgetn_mmap): Handle reading from backup.
	* stdio-common/tst-ungetc.c (main): Add another test.

ChangeLog

@@ -1,3 +1,15 @@
+2002-02-25  Jakub Jelinek  <jakub@redhat.com>
+
+	* libio/iofopen.c (__fopen_maybe_mmap): Set the initial
+	position to fp->_offset if it is set.
+	* stdio-common/Makefile (tests): Add tst-fdopen.
+	* stdio-common/tst-fdopen.c: New test.
+
+2002-02-25  Jakub Jelinek  <jakub@redhat.com>
+
+	* libio/fileops.c (_IO_file_xsgetn_mmap): Handle reading from backup.
+	* stdio-common/tst-ungetc.c (main): Add another test.
+
 2002-02-25  Ulrich Drepper  <drepper@redhat.com>
 
 	* assert/assert-perr.c: Use INTUSE to reference functions and variables

libio/fileops.c

@@ -1197,28 +1197,54 @@ _IO_file_xsgetn_mmap (fp, data, n)
 {
   register _IO_size_t have;
   char *read_ptr = fp->_IO_read_ptr;
+  register char *s = (char *) data;
 
   have = fp->_IO_read_end - fp->_IO_read_ptr;
 
   if (have < n)
     {
-      /* Maybe the read buffer is not yet fully set up.  */
-      fp->_IO_read_ptr = fp->_IO_read_end;
-      if (fp->_IO_read_end < fp->_IO_buf_end
-	  && _IO_file_underflow_mmap (fp) != EOF)
-	have = fp->_IO_read_end - read_ptr;
+      if (__builtin_expect (_IO_in_backup (fp), 0))
+	{
+#ifdef _LIBC
+	  s = __mempcpy (s, read_ptr, have);
+#else
+	  memcpy (s, read_ptr, have);
+	  s += have;
+#endif
+	  n -= have;
+	  _IO_switch_to_main_get_area (fp);
+	  read_ptr = fp->_IO_read_ptr;
+	  have = fp->_IO_read_end - fp->_IO_read_ptr;
+	}
+
+      if (have < n)
+	{
+	  /* Maybe the read buffer is not yet fully set up.  */
+	  fp->_IO_read_ptr = fp->_IO_read_end;
+	  if (fp->_IO_read_end < fp->_IO_buf_end
+	      && _IO_file_underflow_mmap (fp) != EOF)
+	    have = fp->_IO_read_end - read_ptr;
+	}
     }
 
   if (have == 0)
-    fp->_flags |= _IO_EOF_SEEN;
+    {
+      if (s == (char *) data)
+	fp->_flags |= _IO_EOF_SEEN;
+    }
   else
     {
       have = MIN (have, n);
-      memcpy (data, read_ptr, have);
+#ifdef _LIBC
+      s = __mempcpy (s, read_ptr, have);
+#else
+      memcpy (s, read_ptr, have);
+      s += have;
+#endif
       fp->_IO_read_ptr = read_ptr + have;
     }
 
-  return have;
+  return s - (char *) data;
 }
 
 struct _IO_jump_t _IO_file_jumps =

libio/iofopen.c

@@ -53,7 +53,9 @@ __fopen_maybe_mmap (fp)
       if (_IO_SYSSTAT (fp, &st) == 0
 	  && S_ISREG (st.st_mode) && st.st_size != 0
 	  /* Limit the file size to 1MB for 32-bit machines.  */
-	  && (sizeof (ptrdiff_t) > 4 || st.st_size < 1*1024*1024))
+	  && (sizeof (ptrdiff_t) > 4 || st.st_size < 1*1024*1024)
+	  /* Sanity check.  */
+	  && (fp->_offset == _IO_pos_BAD || fp->_offset <= st.st_size))
 	{
 	  /* Try to map the file.  */
 	  void *p;
@@ -72,15 +74,17 @@ __fopen_maybe_mmap (fp)
 		 underflow functions which never tries to read
 		 anything from the file.  */
 	      INTUSE(_IO_setb) (fp, p, (char *) p + st.st_size, 0);
-	      _IO_setg (fp, p, p, p);
+
+	      if (fp->_offset == _IO_pos_BAD)
+		fp->_offset = 0;
+
+	      _IO_setg (fp,  p, p + fp->_offset, p + fp->_offset);
 
 	      if (fp->_mode <= 0)
 		_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_file_jumps_mmap;
 	      else
 		_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_wfile_jumps_mmap;
 	      fp->_wide_data->_wide_vtable = &_IO_wfile_jumps_mmap;
-
-	      fp->_offset = 0;
 	    }
 	}
     }

stdio-common/Makefile

@@ -56,7 +56,7 @@ tests := tstscanf test_rdwr test-popen tstgetln test-fseek \
 	 scanf1 scanf2 scanf3 scanf4 scanf5 scanf7 scanf8 scanf9 scanf10 \
 	 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-perror tst-sprintf tst-rndseek tst-fdopen
 
 test-srcs = tst-unbputc tst-printf
 

stdio-common/tst-fdopen.c

@@ -0,0 +1,49 @@
+/* Test for fdopen bugs.  */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#define assert(x) \
+  if (!(x)) \
+    { \
+      fputs ("test failed: " #x "\n", stderr); \
+      retval = 1; \
+      goto the_end; \
+    }
+
+char buffer[256];
+
+int
+main (int argc, char *argv[])
+{
+  char *name;
+  FILE *fp = NULL;
+  int retval = 0;
+  int c, fd;
+
+  name = tmpnam (NULL);
+  fp = fopen (name, "w");
+  assert (fp != NULL)
+  fputs ("foobar and baz", fp);
+  fclose (fp);
+  fp = NULL;
+
+  fd = open (name, O_RDONLY);
+  assert (fd != -1);
+  assert (lseek (fd, 5, SEEK_SET) == 5);
+  /* The file position indicator associated with the new stream is set to
+     the position indicated by the file offset associated with the file
+     descriptor.  */
+  fp = fdopen (fd, "r");
+  assert (fp != NULL);
+  assert (getc (fp) == 'r');
+  assert (getc (fp) == ' ');
+
+the_end:
+  if (fp != NULL)
+    fclose (fp);
+  unlink (name);
+
+  return retval;
+}

stdio-common/tst-ungetc.c

@@ -18,6 +18,7 @@ main (int argc, char *argv[])
   FILE *fp = NULL;
   int retval = 0;
   int c;
+  char buffer[64];
 
   name = tmpnam (NULL);
   fp = fopen (name, "w");
@@ -40,6 +41,17 @@ main (int argc, char *argv[])
   assert (feof (fp) == 0);
   assert (getc (fp) == c);
   assert (getc (fp) == EOF);
+  fclose (fp);
+  fp = NULL;
+
+  fp = fopen (name, "r");
+  assert (fp != NULL);
+  assert (getc (fp) == 'b');
+  assert (getc (fp) == 'l');
+  assert (ungetc ('b', fp) == 'b');
+  assert (fread (buffer, 1, 64, fp) == 2);
+  assert (buffer[0] == 'b');
+  assert (buffer[1] == 'a');
 
 the_end:
   if (fp != NULL)