hush: fix bug with local environment vars in pipes; simplify parse_stream()

function                                             old     new   delta
parse_stream                                        1238    1218     -20
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-20)             Total: -20 bytes

3 files changed, 45 insertions, 38 deletions

diff --git a/shell/hush.c b/shell/hush.c
index d401948aa..e2259ce38 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -1657,8 +1657,7 @@ static char **o_finalize_list(o_string *o, int n)
 
 /* Expansion can recurse */
 #if ENABLE_HUSH_TICK
-static int process_command_subs(o_string *dest,
-                struct in_str *input, const char *subst_end);
+static int process_command_subs(o_string *dest, struct in_str *input);
 #endif
 static char *expand_string_to_string(const char *str);
 static int parse_stream_dquoted(o_string *dest, struct in_str *input, int dquote_end);
@@ -1814,7 +1813,7 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
 //TODO: can we just stuff it into "output" directly?
                         debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
                         setup_string_in_str(&input, arg);
-                        process_command_subs(&subst_result, &input, NULL);
+                        process_command_subs(&subst_result, &input);
                         debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
                         val = subst_result.data;
                         goto store_val;
@@ -1971,7 +1970,6 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
                         }
                 } /* default: */
                 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
-
                 if (val) {
                         o_addQstr(output, val, strlen(val));
                 }
@@ -2265,7 +2263,7 @@ static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignme
         if (argv_expanded) {
                 argv = argv_expanded;
         } else {
-                argv = expand_strvec_to_strvec(argv);
+                argv = expand_strvec_to_strvec(argv + assignment_cnt);
 #if !BB_MMU
                 nommu_save->argv = argv;
 #endif
@@ -3628,7 +3626,6 @@ static int done_word(o_string *word, struct parse_context *ctx)
                         ctx->ctx_dsemicolon = 0;
                 } else
 #endif
-
                 if (!command->argv /* if it's the first word... */
 #if ENABLE_HUSH_LOOPS
                  && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
@@ -3767,8 +3764,7 @@ static FILE *generate_stream_from_list(struct pipe *head)
 
 /* Return code is exit status of the process that is run. */
 static int process_command_subs(o_string *dest,
-                struct in_str *input,
-                const char *subst_end)
+                struct in_str *input)
 {
         int retcode, ch, eol_cnt;
         o_string result = NULL_O_STRING;
@@ -3777,7 +3773,7 @@ static int process_command_subs(o_string *dest,
         struct in_str pipe_str;
 
         /* Recursion to generate command */
-        retcode = parse_stream(&result, &inner, input, subst_end);
+        retcode = parse_stream(&result, &inner, input, NULL);
         if (retcode != 0)
                 return retcode;  /* syntax error or EOF */
         o_free(&result);
@@ -4236,9 +4232,11 @@ static int parse_stream(o_string *dest, struct parse_context *ctx,
          * A single-quote triggers a bypass of the main loop until its mate is
          * found.  When recursing, quote state is passed in via dest->o_escape. */
 
-        debug_printf_parse("parse_stream entered, end_trigger='%s' dest->o_assignment:%d\n", end_trigger, dest->o_assignment);
-        initialize_context(ctx);
+        debug_printf_parse("parse_stream entered, end_trigger='%s' "
+                "dest->o_assignment:%d\n", end_trigger, dest->o_assignment);
 
+        dest->o_assignment = MAYBE_ASSIGNMENT;
+        initialize_context(ctx);
         is_in_dquote = dest->o_escape;
         while (1) {
                 if (is_in_dquote) {
@@ -4269,51 +4267,47 @@ static int parse_stream(o_string *dest, struct parse_context *ctx,
                         }
                         continue;
                 }
-                /* m is SPECIAL ($,`), IFS, or ORDINARY_IF_QUOTED (*,#)
-                 */
+                /* m is SPECIAL ($,`), IFS, or ORDINARY_IF_QUOTED (*,#) */
                 if (m == CHAR_IFS) {
+                        if (ch == EOF)
+                                goto ret_EOF;
                         if (done_word(dest, ctx)) {
                                 debug_printf_parse("parse_stream return 1: done_word!=0\n");
                                 return 1;
                         }
-                        if (ch == EOF)
-                                goto ret_EOF;
-                        /* If we aren't performing a substitution, treat
-                         * a newline as a command separator.
-                         * [why don't we handle it exactly like ';'? --vda] */
-                        if (end_trigger && ch == '\n') {
+                        if (ch == '\n') {
 #if ENABLE_HUSH_CASE
                                 /* "case ... in <newline> word) ..." -
                                  * newlines are ignored (but ';' wouldn't be) */
-                                if (dest->length == 0 // && argv[0] == NULL
+                                if (ctx->command->argv == NULL
                                  && ctx->ctx_res_w == RES_MATCH
                                 ) {
                                         continue;
                                 }
 #endif
+                                /* Treat newline as a command separator.
+                                 * [why don't we handle it exactly like ';'? --vda] */
                                 done_pipe(ctx, PIPE_SEQ);
                                 dest->o_assignment = MAYBE_ASSIGNMENT;
                         }
                 }
-                if (end_trigger) {
-                        if (strchr(end_trigger, ch)) {
-                                /* Special case: (...word) makes last word terminate,
-                                 * as if ';' is seen */
-                                if (ch == ')') {
-                                        done_word(dest, ctx);
+                if (end_trigger && strchr(end_trigger, ch)) {
+                        /* Special case: (...word) makes last word terminate,
+                         * as if ';' is seen */
+                        if (ch == ')') {
+                                done_word(dest, ctx);
 //err chk?
-                                        done_pipe(ctx, PIPE_SEQ);
-                                        dest->o_assignment = MAYBE_ASSIGNMENT;
-                                }
-                                /* What do we check here? */
-                                if (!HAS_KEYWORDS
-                                 IF_HAS_KEYWORDS(|| (ctx->ctx_res_w == RES_NONE && ctx->old_flag == 0))
-                                ) {
-                                        debug_printf_parse("parse_stream return 0: end_trigger char found\n");
-                                        /* this makes us return 0, not -1 */
-                                        end_trigger = NULL;
-                                        goto ret;
-                                }
+                                done_pipe(ctx, PIPE_SEQ);
+                                dest->o_assignment = MAYBE_ASSIGNMENT;
+                        }
+                        /* What do we check here? */
+                        if (!HAS_KEYWORDS
+                         IF_HAS_KEYWORDS(|| (ctx->ctx_res_w == RES_NONE && ctx->old_flag == 0))
+                        ) {
+                                debug_printf_parse("parse_stream return 0: end_trigger char found\n");
+                                /* this makes us return 0, not -1 */
+                                end_trigger = NULL;
+                                goto ret;
                         }
                 }
                 if (m == CHAR_IFS)
diff --git a/shell/hush_test/hush-vars/var_in_pipes.right b/shell/hush_test/hush-vars/var_in_pipes.right
new file mode 100644
index 000000000..faf65bed4
--- /dev/null
+++ b/shell/hush_test/hush-vars/var_in_pipes.right
@@ -0,0 +1,6 @@
+b=1
+b=2
+b=3
+b=4
+b=5
+b=6
diff --git a/shell/hush_test/hush-vars/var_in_pipes.tests b/shell/hush_test/hush-vars/var_in_pipes.tests
new file mode 100755
index 000000000..3f8cd2729
--- /dev/null
+++ b/shell/hush_test/hush-vars/var_in_pipes.tests
@@ -0,0 +1,7 @@
+b=1 env | grep ^b=
+true | b=2 env | grep ^b=
+a=1 true | b=3 env | grep ^b=
+
+(b=4 env) | grep ^b=
+(true | b=5 env) | grep ^b=
+(a=1 true | b=6 env) | grep ^b=