win32: fix problem interrupting shell loop

It proved to be almost impossible to interrupt a loop like:

   while true; do sleep 1; done

where 'sleep' was an external program, not an applet.  The issue
was introduced by commit 0475b7a64 (win32: convert exit codes).
This passed a POSIX error code to the exit() in wait_for_child()
so a parent was unable to detect when its child was interrupted.

Pass the Windows exit code to exit() instead.  Work around the
changes introduced by commit 790e377273 (win32: revert 'don't set
error mode').

Adds 16-32 bytes.

1 files changed, 13 insertions, 11 deletions

diff --git a/win32/process.c b/win32/process.c
index 9a5ab417a..34ef3cffa 100644
--- a/win32/process.c
+++ b/win32/process.c
@@ -482,24 +482,22 @@ static int exit_code_to_wait_status_cmd(DWORD exit_code, const char *cmd)
         return status << 8;
 }
 
-static int exit_code_to_posix_cmd(DWORD exit_code, const char *cmd)
-{
-        int status = exit_code_to_wait_status_cmd(exit_code, cmd);
-
-        if (WIFSIGNALED(status))
-                return 128 + WTERMSIG(status);
-        return WEXITSTATUS(status);
-}
-
 static NORETURN void wait_for_child(HANDLE child, const char *cmd)
 {
         DWORD code;
+        int status;
 
         kill_child_ctrl_handler(GetProcessId(child));
         SetConsoleCtrlHandler(kill_child_ctrl_handler, TRUE);
         WaitForSingleObject(child, INFINITE);
         GetExitCodeProcess(child, &code);
-        exit(exit_code_to_posix_cmd(code, cmd));
+        // We don't need the wait status, but get it anyway so the error
+        // message can include the command.  In such cases we pass the
+        // exit status to exit() so our caller won't repeat the message.
+        status = exit_code_to_wait_status_cmd(code, cmd);
+        if (!WIFSIGNALED(status) && code > 0xff)
+                code = WEXITSTATUS(status);
+        exit((int)code);
 }
 
 int
@@ -949,5 +947,9 @@ int exit_code_to_wait_status(DWORD exit_code)
 
 int exit_code_to_posix(DWORD exit_code)
 {
-        return exit_code_to_posix_cmd(exit_code, NULL);
+        int status = exit_code_to_wait_status(exit_code);
+
+        if (WIFSIGNALED(status))
+                return 128 + WTERMSIG(status);
+        return WEXITSTATUS(status);
 }