[patch,libgfortran] PR88776 Namelist read from stdin: loss of data

[Jerry DeLisle]

On 1/12/19 2:35 PM, Jerry DeLisle wrote:
> Hi all,
> 
> As stated in the PR, the problem turns out to be an ungraceful return 
> after an error.  Most namelist errors go through nml_err_ret, The one I 
> am removing did not and in the unique case of UNIT=5 after the error it 
> falls through and hits some code which modifies pointers to the namelist 
> data structures.
> 
> This patch fixes it.
> 
> Regression tested on x86-64 and manually tested with a redirection to 
> stdin. (cat somefile | ./a.out )
> 
> I plan to commit today as simple along with a new testcase.
> 
> Regards.
> 
> Jerry
> 
> 2019-01-12  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
> 
>  Â Â Â Â PR libfortran/88776
>  Â Â Â Â * io/list_read.c (namelist_read): Use nml_err_ret path on
>  Â Â Â Â read error, not based on stdin_unit.

Committed.

While doing extra testing on the test case for this PR, I noticed a 
memory leak with valgrind.

The attached patch fixes this. The problem is when opening a file with a 
preconnected unit, the previously initialized format buffer (fbuf) in 
the preconnected unit structure gets abandoned (pointer overwritten by 
the new fbuf), and a new one allocated later in the code path.

I will commit this additional patch and the test case as simple and obvious.

Regression tested on x86_64. Valgrind clean.

Regards,

Jerry

2019-01-13  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

    PR libfortran/88776
    * io/open.c (newunit): Free format buffer if the unit specified is
    for stdin, stdout, or stderr.

2019-01-13  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

    PR libfortran/88776
    * gfortran.dg/namelist_96.f90: New test.


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