PATCH: _exit in zexecve when the interpreter doesn't work

[Mikael Magnusson <mikachu@xxxxxxxxx>]

---

Otherwise we keep searching path after printing the error message, which is
unexpected. I checked what bash does here and it also returns 126 and stops
searching, which seems more reasonable.

Reported on IRC:

23:35:26 <bitblt> Having two identically named scripts in the path, e.g. 
with PATH having both ~/.bin and /usr/local/bin in it and a foobar script 
existing in both ~/.bin and /usr/local/bin, if I have a 'bad' shebang in 
the first one of them, like a non-existing interpreter path, then it 
prints the error, and continues to try and execute the next 
similarily-named script in the path successfully?
23:35:42 <bitblt> Is this expected zsh functionality? Bash just errors out 
and stops
23:42:51 <Riviera> bitblt: that's apparently indeed what zsh does. how 
weird.
23:43:37 <Riviera> bitblt: fwiw i do not see it documented or 
configurable, but i really don't have a clue about zsh. i'm pretty certain 
though that i'd not want this behaviour.
23:43:43 <bitblt> Is this a bug or some kind of weird feature that is by 
default on?
23:44:38 <bitblt> yeah this caught me off guard too, and I almost blamed 
another thing before I discover this behavior
23:53:18 <Mikachu> it's because the missing interpreter sets the errno to 
ENOENT which is (mis)interpreted as "no file was found at this path entry, 
keep searching"

 Src/exec.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Src/exec.c b/Src/exec.c
index 8216ca727d..f5a615b182 100644
--- a/Src/exec.c
+++ b/Src/exec.c
@@ -557,10 +557,11 @@ zexecve(char *pth, char **argv, char **newenvp)
 		    for (t0 = 0; t0 != ct; t0++)
 			if (execvebuf[t0] == '\n')
 			    break;
-		    if (t0 == ct)
+		    if (t0 == ct) {
 			zerr("%s: bad interpreter: %s: %e", pth,
 			     metafy(execvebuf + 2, -1, META_STATIC), eno);
-		    else {
+			_exit(126);
+		    } else {
 			while (inblank(execvebuf[t0]))
 			    execvebuf[t0--] = '\0';
 			for (ptr = execvebuf + 2; *ptr && *ptr == ' '; ptr++);
@@ -584,6 +585,7 @@ zexecve(char *pth, char **argv, char **newenvp)
 			    }
 			    zerr("%s: bad interpreter: %s: %e", pth,
 				 metafy(ptr2, -1, META_STATIC), eno);
+			    _exit(126);
 			} else if (*ptr) {
 			    *ptr = '\0';
 			    argv[-2] = ptr2;
-- 
2.38.1