Commit Graph

2 Commits

Author SHA1 Message Date
Adhemerval Zanella
edbdf872ae Fix tst-memstream3 build failure
Add string.h to avoid tst-memstream3 build failure in some environments:

 tst-memstream3.c:32:17: error: implicit declaration of function 'strcmp' [-Werror=implicit-function-declaration]
  # define STRCMP strcmp
                  ^
 tst-memstream3.c:96:7: note: in expansion of macro 'STRCMP'
    if (STRCMP (buf, W("b")) != 0)

Checked on x86_64.

	* libio/tst-memstream3.c: Include string.h.
2016-10-02 10:24:32 -03:00
Adhemerval Zanella
645f97ced4 libio: Multiple fixes for open_{w}memstram (BZ#18241 and BZ#20181)
This patches fixes multiples issues on open_{w}memstream reported on both
BZ#18241 and BZ#20181:

  - failed fseek does not set errno.
  - negative offset in fseek fails even when resulting position is
    a valid one.
  - a flush after write if the current write position is not at the
    end of the stream currupt data.

The main fix is on seek operation for memstream (_IO_{w}str_seekoff), where
both _IO_read_ptr and _IO_read_end pointer are updated if a write operation
has occured (similar to default file operations).  Also, to calculate the
offset on both read and write pointers, a temporary value is instead of
updating the argument supplied value.  Negative offset are valid if resulting
internal pointer is within the range of _IO_{read,write}_base and
_IO_{read,write}_end.

Also POSIX states that a null or wide null shall be appended to the current
buffer iff a write moves the position to a value larger than the current
lenght.  Current implementation appends a null or wide null regardless
of this condition.  This patch fixes it by removing the 'else' condition
on _IO_{w}mem_sync.

Checked on x86_64.

	[BZ #18241]
	[BZ #20181]
	* libio/Makefile (test): Add tst-memstream3 and tst-wmemstream3.
	* libio/memstream.c (_IO_mem_sync): Only append a null byte if
	write position is at the end the buffer.
	* libio/wmemstream.c (_IO_wmem_sync): Likewise.
	* libio/strops.c (_IO_str_switch_to_get_mode): New function.
	(_IO_str_seekoff): Set correct offset from negative displacement and
	set EINVAL for invalid ones.
	* libio/wstrops.c (enlarge_userbuf): Use correct function to calculate
	buffer length.
	(_IO_wstr_switch_to_get_mode): New function.
	(_IO_wstr_seekoff): Set correct offset from negative displacement and
	set EINVAL for invalid ones.
	* libio/tst-memstream3.c: New file.
	* libio/tst-wmemstream3.c: Likewise.
	* manual/examples/memstrm.c: Remove warning when priting size_t.
2016-09-30 09:14:15 -07:00