hush: fix "export not_yet_defined_var", fix parsing of "cmd | }"

 corner case; improve hush_leaktool.sh;
 fix some false positives in testsuite

function                                             old     new   delta
builtin_export                                       191     206     +15
parse_stream                                        2196    2200      +4

1 files changed, 25 insertions, 20 deletions

diff --git a/shell/hush.c b/shell/hush.c
index c542b7dd9..2c2750fc8 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -4459,10 +4459,6 @@ static int done_word(o_string *word, struct parse_context *ctx)
                         }
                 }
                 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
-//SEGV, but good idea.
-//              command->argv = add_string_to_strings(command->argv, word->data);
-//              word->data = NULL;
-//              word->length = 0;
                 debug_print_strings("word appended to argv", command->argv);
         }
 
@@ -5481,14 +5477,16 @@ static struct pipe *parse_stream(char **pstring,
                  * } is an ordinary char in this case, even inside { cmd; }
                  * Pathological example: { ""}; } should exec "}" cmd
                  */
-                if (ch == '}'
-                 && !(IS_NULL_PIPE(ctx.pipe)
-                     && IS_NULL_CMD(ctx.command)
-                     && dest.length == 0
-                     && !dest.o_quoted
-                    )
-                ) {
-                        goto ordinary_char;
+                if (ch == '}') {
+                        if (!IS_NULL_CMD(ctx.command) /* cmd } */
+                         || dest.length != 0 /* word} */
+                         || dest.o_quoted    /* ""} */
+                        ) {
+                                goto ordinary_char;
+                        }
+                        if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
+                                goto skip_end_trigger;
+                        /* else: } does terminate a group */
                 }
 
                 if (end_trigger && end_trigger == ch
@@ -5531,6 +5529,7 @@ static struct pipe *parse_stream(char **pstring,
                                 return ctx.list_head;
                         }
                 }
+ skip_end_trigger:
                 if (is_ifs)
                         continue;
 
@@ -6420,12 +6419,11 @@ static int builtin_export(char **argv)
         }
 
         do {
-                const char *value;
                 char *name = *argv;
 
-                value = strchr(name, '=');
-                if (!value) {
-                        /* They are exporting something without a =VALUE */
+                /* So far we do not check that name is valid */
+                if (strchr(name, '=') == NULL) {
+                        /* Exporting a name without a =VALUE */
                         struct variable *var;
 
                         var = get_local_var(name);
@@ -6433,12 +6431,19 @@ static int builtin_export(char **argv)
                                 var->flg_export = 1;
                                 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
                                 putenv(var->varstr);
+                                continue;
                         }
-                        /* bash does not return an error when trying to export
-                         * an undefined variable.  Do likewise. */
-                        continue;
+                        /* Exporting non-existing variable.
+                         * bash does not put it in environment,
+                         * but remembers that it is exported,
+                         * and does put it in env when it is set later.
+                         * We just set it to "" and export. */
+                        name = xasprintf("%s=", name);
+                } else {
+                        /* Exporting VAR=VALUE */
+                        name = xstrdup(name);
                 }
-                set_local_var(xstrdup(name), 1, 0);
+                set_local_var(name, 1, 0);
         } while (*++argv);
 
         return EXIT_SUCCESS;