[Ada] text_io fixes

[Arnaud Charlet <charlet at adacore dot com>]

Tested on i686-linux, committed on trunk

When Before_LM and Before_LM_PM are both set on entry in Skip_Line, we
reset the Before_LM_PM marker prior to taking it into account in the page
count (which is incorrect because if Before_LM_PM is set, then we know that
Before_LM is also set). We need to defer the reset of Before_LM_PM until
it has been taken into account (which means that within Skip_Line there
is a section of code during which the invariant (Before_LM_PM =>
Before_LM) is transiently violated, which is fine as long as it is
always restored prior to exiting that procedure).

The program below must produce the following ouput:
Page number 2
Line number 2
[Page 1][Line 1]Line 1.<EoL>
[Page 1][Line 2]Line 2.<EoL>
[Page 1][Line 3]Line 3.<EoL><EoP>
[Page 2][Line 1]<EoF>

with Ada.Text_IO; use  Ada.Text_IO;
procedure Test_IO is
  F: File_Type;
  C: Character;
  E: Boolean := True;
begin
  Create (F, Mode => Out_File);
  Put_Line (F, "Line 1.");
  Put_Line (F, "Line 2.");
  Put_Line (F, "Line 3.");
  Set_Line (F, 2);
  Put_Line ("Page number" & Count'Image (Page (F)));
  Put_Line ("Line number" & Count'Image (Line (F)));
  Reset (F, Mode => In_File);
  loop
    if E then
      Put ("[Page" & Count'Image (Page (F)) & "][Line" & Count'Image (Line (F)) & ']');
    end if;
    if End_of_File (F) then
      Put_Line ("<EoF>");
      exit;
    end if;
    if End_of_Line (F) then
      Put ("<EoL>");
    end if;
    if End_of_Page (F) then
      Put ("<EoP>");
    end if;
    if End_of_Line (F) then
      New_Line;
    end if;
    Look_Ahead (F, C, E);
    if E then
      Skip_Line (F);
    else
      Get (F, C);
      Put (C);
    end if;
  end loop;
end Test_IO;

2007-06-06  Thomas Quinot  <quinot@adacore.com>

	* a-textio.ads, a-textio.adb (Write): Add explicit size clause for the
	C imported variable.
	(Skip_Line): Do not reset Before_LM_PM immediately when Before_LM is set
	on entry.

Attachment: difs
Description: Text document