[PATCH] hush: Fix assignments being misinterpreted as commands

[Sean Anderson <seanga2@gmail.com>]

On 2/28/21 6:40 PM, Heinrich Schuchardt wrote:
> Am 28. Februar 2021 22:29:51 MEZ schrieb Sean Anderson <seanga2@gmail.com>:
>> If there were no variable substitutions in a command, then initial
>> assignments would be misinterpreted as commands, instead of being
>> skipped
>> over. This is demonstrated by the following example:
>>
>> 	=> foo=bar echo baz
> 
> The commit message does not explain why this patch is needed.

This is a bug I noticed while writing some tests of hush.

> What shall be the value off foo after this line?

It should be bar. This is an existing difference when compared with
bash. For example, without this patch, we have

	=> foo=bar echo $foo
	bar
	=> echo $foo
	bar

> 
> What will be the output of
> 
> foo=bar echo ${foo}
> 
> with and without yor patch?

It is the same.

--Sean

> 
> Best regards
> 
> Heinrich
> 
> 
>> 	Unknown command 'foo=bar' - try 'help'
>>
>> Signed-off-by: Sean Anderson <seanga2@gmail.com>
>> ---
>>
>> common/cli_hush.c    | 2 +-
>> test/cmd/test_echo.c | 2 ++
>> 2 files changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/common/cli_hush.c b/common/cli_hush.c
>> index b7f0f0ff41..1b9bef64b6 100644
>> --- a/common/cli_hush.c
>> +++ b/common/cli_hush.c
>> @@ -1672,7 +1672,7 @@ static int run_pipe_real(struct pipe *pi)
>> 			return -1;
>> 		}
>> 		/* Process the command */
>> -		return cmd_process(flag, child->argc, child->argv,
>> +		return cmd_process(flag, child->argc - i, child->argv + i,
>> 				   &flag_repeat, NULL);
>> #endif
>> 	}
>> diff --git a/test/cmd/test_echo.c b/test/cmd/test_echo.c
>> index 4183cf75bb..13e1fb7c82 100644
>> --- a/test/cmd/test_echo.c
>> +++ b/test/cmd/test_echo.c
>> @@ -33,6 +33,8 @@ static struct test_data echo_data[] = {
>> 	 */
>> 	{"setenv jQx X; echo \"a)\" ${jQx} 'b)' '${jQx}' c) ${jQx}; setenv
>> jQx",
>> 	 "a) X b) ${jQx} c) X"},
>> +	/* Test shell variable assignments without substitutions */
>> +	{"foo=bar echo baz", "baz"},
>> 	/* Test handling of shell variables. */
>> 	{"setenv jQx; for jQx in 1 2 3; do echo -n \"${jQx}, \"; done; echo;",
>> 	 "1, 2, 3, "},
>