[bug] wrong exit status upon (e) flag fatal errors in if/while conditions

[bug] wrong exit status upon (e) flag fatal errors in if/while conditions

[Stephane Chazelas]

$ a='${' zsh -c 'if : ${(e)a}; then echo x; fi; echo y'; echo $?
zsh:1: bad substitution
0
$ a='${' zsh -c 'if : ${(e)a}; then echo x; fi; echo y'; echo $?
zsh:1: bad substitution
0

That's when the (e) flag is used in the condition part of an
"if" or "while" (not "until") statement at least.

The shell aborts with an error message but with a success exit
status.

Also, the description of the X flag suggests that error should
be "silently ignored":

DOC> X
DOC>      With this flag, parsing errors occurring with the Q, e and # flags
DOC>      or the pattern matching forms such as '${NAME#PATTERN}' are
DOC>      reported.  Without the flag, errors are silently ignored.

See also:

$ a='$(echo ")' zsh -c 'if : ${(Xe)a}; then echo x; fi; echo y'; echo $?
zsh:1: unmatched "
zsh:1: parse error
0
$ a='$(echo ")' zsh -c 'if : ${(e)a}; then echo x; fi; echo y'; echo $?
zsh:1: unmatched "
x
y
0

Here, the X flag does have an effect, but an error is still
reported (even if it doesn't abort the shell) without it.

-- 
Stephane

Re: [bug] wrong exit status upon (e) flag fatal errors in if/while conditions

[Peter Stephenson]

> On 05 May 2021 at 12:07 Stephane Chazelas <stephane@chazelas.org> wrote:
> $ a='${' zsh -c 'if : ${(e)a}; then echo x; fi; echo y'; echo $?
> zsh:1: bad substitution
> 0
> $ a='${' zsh -c 'if : ${(e)a}; then echo x; fi; echo y'; echo $?
> zsh:1: bad substitution
> 0
> 
> That's when the (e) flag is used in the condition part of an
> "if" or "while" (not "until") statement at least.
> 
> The shell aborts with an error message but with a success exit
> status.

I can do this one; it's quite obvious looking at the code, I think...

BTW this is somewhat obscurely cut and pasted, the actual commit
will come straight from the Linux machine, so don't worry about
any line endings here.

pws

diff --git a/Src/loop.c b/Src/loop.c
index 41b2e5627..aa733a2cb 100644
--- a/Src/loop.c
+++ b/Src/loop.c
@@ -583,7 +583,7 @@ execif(Estate state, int do_exec)
        cmdpop();
     } else {
        noerrexit = olderrexit;
-       if (!retflag)
+       if (!retflag && !errflag)
            lastval = 0;
     }
     state->pc = end;
diff --git a/Test/A01grammar.ztst b/Test/A01grammar.ztst
index 35a04e7d5..88fc8606e 100644
--- a/Test/A01grammar.ztst
+++ b/Test/A01grammar.ztst
@@ -939,3 +939,8 @@ F:Note that the behaviour of 'exit' inside try-list inside a function is unspeci
  $ZTST_testdir/../Src/zsh -fc '{ ( ) } always { echo foo }'
 0:exec last command optimization inhibited for try/always
 >foo
+
+ a='${'
+ if : ${(e)a}; then echo x; fi
+1:Status on bad substitution in if without else
+?(eval):2: bad substitution