ash: correctly identify applet in getopt() error messages

With the default configuration most applets are run from the shell
via run_noexec_applet_and_exit().  If the applet runs getopt() and
an error is detected the message takes the form:

   sh: unknown option -- q

This happens because mingw-w64's implementation of getopt() uses
the global variable __argv[0] as the name of the program.

Avoid the misleading message by setting __argv[0] as appropriate.

1 files changed, 2 insertions, 0 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 8cc7a5c75..3d6f25802 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -8689,6 +8689,8 @@ tryexec(IF_FEATURE_SH_STANDALONE(int applet_no,) const char *cmd, char **argv, c
                 struct forkshell *fs = (struct forkshell *)sticky_mem_start;
                 if (applet_main[applet_no] != ash_main ||
                                 (fs && fs->fpid == FS_SHELLEXEC)) {
+                        /* mingw-w64's getopt() uses __argv[0] as the program name */
+                        __argv[0] = (char *)cmd;
 # else
                 if (APPLET_IS_NOEXEC(applet_no)) {
 # endif