[gcc r10-10511] Properly reset the port handle when closing

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

https://gcc.gnu.org/g:d800a6f6c03e404a5f033299d9fd1c5caa3b7738

commit r10-10511-gd800a6f6c03e404a5f033299d9fd1c5caa3b7738
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 87143e23531..aa3c0134222 100644
--- a/gcc/ada/libgnat/g-sercom__linux.adb
+++ b/gcc/ada/libgnat/g-sercom__linux.adb
@@ -318,6 +318,7 @@ 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 d5e2344524f..51fc0ac8953 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");