[gcc r13-1437] [Ada] Single character argument in call to Quote_Argument raises error

[gcc r13-1437] [Ada] Single character argument in call to Quote_Argument raises error

[Pierre-Marie de Rodat]

https://gcc.gnu.org/g:1fde86bba55ea61b56f79798c6ac4cc6808e51a1

commit r13-1437-g1fde86bba55ea61b56f79798c6ac4cc6808e51a1
Author: Justin Squirek <squirek@adacore.com>
Date:   Thu May 26 15:15:46 2022 +0000

    [Ada] Single character argument in call to Quote_Argument raises error
    
    This patch corrects an issue in the compiler whereby calling
    Quote_Argument with an argument that is of size 1 may lead to a
    CONSTRAINT_ERROR raised at runtime due to an undersized buffer.
    
    gcc/ada/
    
            * libgnat/s-os_lib.adb (Quote_Argument): Modify the result
            buffer size calculation to handle the case where Arg'Length is
            1.

Diff:
---
 gcc/ada/libgnat/s-os_lib.adb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/ada/libgnat/s-os_lib.adb b/gcc/ada/libgnat/s-os_lib.adb
index 5af65866b2b..53dfbf93f18 100644
--- a/gcc/ada/libgnat/s-os_lib.adb
+++ b/gcc/ada/libgnat/s-os_lib.adb
@@ -1940,7 +1940,7 @@ package body System.OS_Lib is
       procedure Quote_Argument (Arg : in out String_Access) is
          J            : Positive := 1;
          Quote_Needed : Boolean  := False;
-         Res          : String (1 .. Arg'Length * 2);
+         Res          : String (1 .. Arg'Length * 2 + 2);
 
       begin
          if Arg (Arg'First) /= '"' or else Arg (Arg'Last) /= '"' then