sh: Send the "xyz: not found" message to redirected fd 2.

This also fixes that trying to execute a non-regular file with a command
name without '/' returns 127 instead of 126.
The fix is rather simplistic: treat CMDUNKNOWN as if the command were found
as an external program. The resulting fork is a bit wasteful but executing
unknown commands should not be very frequent.

PR:		bin/137659

2 files changed, 3 insertions, 7 deletions

diff --git a/bin/sh/eval.c b/bin/sh/eval.c
index 7978b84..5ba244d 100644
--- a/bin/sh/eval.c
+++ b/bin/sh/eval.c
@@ -713,12 +713,7 @@ evalcommand(union node *cmd, int flags, struct backcmd *backcmd)
 				do_clearcmdentry = 1;
 			}
 
-		find_command(argv[0], &cmdentry, 1, path);
-		if (cmdentry.cmdtype == CMDUNKNOWN) {	/* command not found */
-			exitstatus = 127;
-			flushout(&errout);
-			return;
-		}
+		find_command(argv[0], &cmdentry, 0, path);
 		/* implement the bltin builtin here */
 		if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) {
 			for (;;) {
@@ -740,7 +735,7 @@ evalcommand(union node *cmd, int flags, struct backcmd *backcmd)
 
 	/* Fork off a child process if necessary. */
 	if (cmd->ncmd.backgnd
-	 || (cmdentry.cmdtype == CMDNORMAL
+	 || ((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN)
 	    && ((flags & EV_EXIT) == 0 || have_traps()))
 	 || ((flags & EV_BACKCMD) != 0
 	    && (cmdentry.cmdtype != CMDBUILTIN
diff --git a/bin/sh/exec.c b/bin/sh/exec.c
index 8107821..f9d3c22 100644
--- a/bin/sh/exec.c
+++ b/bin/sh/exec.c
@@ -429,6 +429,7 @@ loop:
 			outfmt(out2, "%s: %s\n", name, strerror(e));
 	}
 	entry->cmdtype = CMDUNKNOWN;
+	entry->u.index = 0;
 	return;
 
 success: