[gcc r11-9691] Properly reset the port handle when closing

[Eric Botcazou <ebotcazou@gcc.gnu.org>]

https://gcc.gnu.org/g:4c649dc71189f20ab8ed09b03a7353299f1022c8

commit r11-9691-g4c649dc71189f20ab8ed09b03a7353299f1022c8
Author: Pascal Obry <obry@adacore.com>
Date:   Thu Mar 24 11:30:05 2022 +0100

    Properly reset the port handle when closing
    
    When the serial port is closed, we need to ensure that the port handle is
    properly reset for it to be detected as closed.
    
    gcc/ada/
            PR ada/104767
            * libgnat/g-sercom__mingw.adb (Close): Reset port handle to -1.
            * libgnat/g-sercom__linux.adb (Close): Likewise.

Diff:
---
 gcc/ada/libgnat/g-sercom__linux.adb | 1 +
 gcc/ada/libgnat/g-sercom__mingw.adb | 1 +
 2 files changed, 2 insertions(+)

diff --git a/gcc/ada/libgnat/g-sercom__linux.adb b/gcc/ada/libgnat/g-sercom__linux.adb
index f7212e87cca..1ad48ca1720 100644
--- a/gcc/ada/libgnat/g-sercom__linux.adb
+++ b/gcc/ada/libgnat/g-sercom__linux.adb
@@ -382,6 +382,7 @@ package body GNAT.Serial_Communications is
    begin
       if Port.H /= -1 then
          Res := close (int (Port.H));
+         Port.H := -1;
       end if;
    end Close;
 
diff --git a/gcc/ada/libgnat/g-sercom__mingw.adb b/gcc/ada/libgnat/g-sercom__mingw.adb
index a0da5ff9434..1cf50905200 100644
--- a/gcc/ada/libgnat/g-sercom__mingw.adb
+++ b/gcc/ada/libgnat/g-sercom__mingw.adb
@@ -70,6 +70,7 @@ package body GNAT.Serial_Communications is
    begin
       if Port.H /= -1 then
          Success := CloseHandle (HANDLE (Port.H));
+         Port.H := -1;
 
          if Success = Win32.FALSE then
             Raise_Error ("error closing the port");