hush: fix some TODOs. TODO in export builting: +250 bytes.

 simplify unexpected EOF handling.

function                                             old     new   delta
builtin_export                                       117     374    +257
o_reset_to_empty_unquoted                              -      21     +21
parse_stream                                        1926    1929      +3
syntax_error_unterm_ch                                31      32      +1
handle_dollar                                        644     641      -3
parse_stream_dquoted                                 307     298      -9
add_till_backquote                                   106      97      -9
add_till_closing_paren                               303     286     -17
o_reset                                               21       -     -21
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 3/4 up/down: 282/-59)           Total: 223 bytes

3 files changed, 89 insertions, 51 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 422fc63f6..e3dfa0673 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -701,12 +701,19 @@ static void syntax_error_at(unsigned lineno, const char *msg)
         die_if_script(lineno, "syntax error at '%s'", msg);
 }
 
+/* It so happens that all such cases are totally fatal
+ * even if shell is interactive: EOF while looking for closing
+ * delimiter. There is nowhere to read stuff from after that,
+ * it's EOF! The only choice is to terminate.
+ */
+static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
 static void syntax_error_unterm_ch(unsigned lineno, char ch)
 {
         char msg[2];
         msg[0] = ch;
         msg[1] = '\0';
         die_if_script(lineno, "syntax error: unterminated %s", msg);
+        xfunc_die();
 }
 
 static void syntax_error_unterm_str(unsigned lineno, const char *s)
@@ -1433,7 +1440,7 @@ static void setup_string_in_str(struct in_str *i, const char *s)
  */
 #define B_CHUNK  (32 * sizeof(char*))
 
-static void o_reset(o_string *o)
+static void o_reset_to_empty_unquoted(o_string *o)
 {
         o->length = 0;
         o->o_quoted = 0;
@@ -4043,7 +4050,7 @@ static int done_word(o_string *word, struct parse_context *ctx)
                 ) {
                         debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
                         if (reserved_word(word, ctx)) {
-                                o_reset(word);
+                                o_reset_to_empty_unquoted(word);
                                 debug_printf_parse("done_word return %d\n",
                                                 (ctx->ctx_res_w == RES_SNTX));
                                 return (ctx->ctx_res_w == RES_SNTX);
@@ -4099,7 +4106,7 @@ static int done_word(o_string *word, struct parse_context *ctx)
         }
 #endif
 
-        o_reset(word);
+        o_reset_to_empty_unquoted(word);
 
         debug_printf_parse("done_word return 0\n");
         return 0;
@@ -4249,7 +4256,7 @@ static int redirect_opt_num(o_string *o)
         num = bb_strtou(o->data, NULL, 10);
         if (errno || num < 0)
                 return -1;
-        o_reset(o);
+        o_reset_to_empty_unquoted(o);
         return num;
 }
 
@@ -4458,7 +4465,6 @@ static int parse_group(o_string *dest, struct parse_context *ctx,
                 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
                 //command->fname = dest->data;
                 command->grp_type = GRP_FUNCTION;
-//TODO: review every o_reset() location... do they handle all o_string fields correctly?
                 memset(dest, 0, sizeof(*dest));
         }
 #endif
@@ -4510,40 +4516,39 @@ static int parse_group(o_string *dest, struct parse_context *ctx,
 
 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
 /* Subroutines for copying $(...) and `...` things */
-static int add_till_backquote(o_string *dest, struct in_str *input);
+static void add_till_backquote(o_string *dest, struct in_str *input);
 /* '...' */
-static int add_till_single_quote(o_string *dest, struct in_str *input)
+static void add_till_single_quote(o_string *dest, struct in_str *input)
 {
         while (1) {
                 int ch = i_getch(input);
                 if (ch == EOF) {
                         syntax_error_unterm_ch('\'');
-                        return 1;
+                        /*xfunc_die(); - redundant */
                 }
                 if (ch == '\'')
-                        return 0;
+                        return;
                 o_addchr(dest, ch);
         }
 }
 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
-static int add_till_double_quote(o_string *dest, struct in_str *input)
+static void add_till_double_quote(o_string *dest, struct in_str *input)
 {
         while (1) {
                 int ch = i_getch(input);
                 if (ch == EOF) {
                         syntax_error_unterm_ch('"');
-                        return 1;
+                        /*xfunc_die(); - redundant */
                 }
                 if (ch == '"')
-                        return 0;
+                        return;
                 if (ch == '\\') {  /* \x. Copy both chars. */
                         o_addchr(dest, ch);
                         ch = i_getch(input);
                 }
                 o_addchr(dest, ch);
                 if (ch == '`') {
-                        if (add_till_backquote(dest, input))
-                                return 1;
+                        add_till_backquote(dest, input);
                         o_addchr(dest, ch);
                         continue;
                 }
@@ -4564,22 +4569,22 @@ static int add_till_double_quote(o_string *dest, struct in_str *input)
  * Example                               Output
  * echo `echo '\'TEST\`echo ZZ\`BEST`    \TESTZZBEST
  */
-static int add_till_backquote(o_string *dest, struct in_str *input)
+static void add_till_backquote(o_string *dest, struct in_str *input)
 {
         while (1) {
                 int ch = i_getch(input);
                 if (ch == EOF) {
                         syntax_error_unterm_ch('`');
-                        return 1;
+                        /*xfunc_die(); - redundant */
                 }
                 if (ch == '`')
-                        return 0;
+                        return;
                 if (ch == '\\') {
                         /* \x. Copy both chars unless it is \` */
                         int ch2 = i_getch(input);
                         if (ch2 == EOF) {
                                 syntax_error_unterm_ch('`');
-                                return 1;
+                                /*xfunc_die(); - redundant */
                         }
                         if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
                                 o_addchr(dest, ch);
@@ -4600,14 +4605,14 @@ static int add_till_backquote(o_string *dest, struct in_str *input)
  * echo $(echo 'TEST)' BEST)            TEST) BEST
  * echo $(echo \(\(TEST\) BEST)         ((TEST) BEST
  */
-static int add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
+static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
 {
         int count = 0;
         while (1) {
                 int ch = i_getch(input);
                 if (ch == EOF) {
                         syntax_error_unterm_ch(')');
-                        return 1;
+                        /*xfunc_die(); - redundant */
                 }
                 if (ch == '(')
                         count++;
@@ -4623,14 +4628,12 @@ static int add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl
                 }
                 o_addchr(dest, ch);
                 if (ch == '\'') {
-                        if (add_till_single_quote(dest, input))
-                                return 1;
+                        add_till_single_quote(dest, input);
                         o_addchr(dest, ch);
                         continue;
                 }
                 if (ch == '"') {
-                        if (add_till_double_quote(dest, input))
-                                return 1;
+                        add_till_double_quote(dest, input);
                         o_addchr(dest, ch);
                         continue;
                 }
@@ -4639,13 +4642,12 @@ static int add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl
                         ch = i_getch(input);
                         if (ch == EOF) {
                                 syntax_error_unterm_ch(')');
-                                return 1;
+                                /*xfunc_die(); - redundant */
                         }
                         o_addchr(dest, ch);
                         continue;
                 }
         }
-        return 0;
 }
 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
 
@@ -4786,8 +4788,7 @@ static int handle_dollar(o_string *as_string,
 #  if !BB_MMU
                         pos = dest->length;
 #  endif
-                        if (add_till_closing_paren(dest, input, true))
-                                return 1;
+                        add_till_closing_paren(dest, input, true);
 #  if !BB_MMU
                         if (as_string) {
                                 o_addstr(as_string, dest->data + pos);
@@ -4805,8 +4806,7 @@ static int handle_dollar(o_string *as_string,
 #  if !BB_MMU
                 pos = dest->length;
 #  endif
-                if (add_till_closing_paren(dest, input, false))
-                        return 1;
+                add_till_closing_paren(dest, input, false);
 #  if !BB_MMU
                 if (as_string) {
                         o_addstr(as_string, dest->data + pos);
@@ -4862,8 +4862,7 @@ static int parse_stream_dquoted(o_string *as_string,
         /* note: can't move it above ch == dquote_end check! */
         if (ch == EOF) {
                 syntax_error_unterm_ch('"');
-                debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
-                return 1;
+                /*xfunc_die(); - redundant */
         }
         next = '\0';
         if (ch != '\n') {
@@ -4872,11 +4871,9 @@ static int parse_stream_dquoted(o_string *as_string,
         debug_printf_parse(": ch=%c (%d) escape=%d\n",
                                         ch, ch, dest->o_escape);
         if (ch == '\\') {
-//TODO: check interactive behavior
                 if (next == EOF) {
                         syntax_error("\\<eof>");
-                        debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
-                        return 1;
+                        xfunc_die();
                 }
                 /* bash:
                  * "The backslash retains its special meaning [in "..."]
@@ -4904,8 +4901,7 @@ static int parse_stream_dquoted(o_string *as_string,
                 //int pos = dest->length;
                 o_addchr(dest, SPECIAL_VAR_SYMBOL);
                 o_addchr(dest, 0x80 | '`');
-                if (add_till_backquote(dest, input))
-                        return 1;
+                add_till_backquote(dest, input);
                 o_addchr(dest, SPECIAL_VAR_SYMBOL);
                 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
                 goto again;
@@ -4982,16 +4978,17 @@ static struct pipe *parse_stream(char **pstring,
 
                         if (heredoc_cnt) {
                                 syntax_error_unterm_str("here document");
-                                goto parse_error;
+                                xfunc_die();
                         }
                         if (done_word(&dest, &ctx)) {
-                                goto parse_error;
+                                xfunc_die();
                         }
                         o_free(&dest);
                         done_pipe(&ctx, PIPE_SEQ);
                         pi = ctx.list_head;
                         /* If we got nothing... */
-// TODO: test script consisting of just "&"
+                        /* (this makes bare "&" cmd a no-op.
+                         * bash says: "syntax error near unexpected token '&'") */
                         if (pi->num_cmds == 0
                             IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
                         ) {
@@ -5182,7 +5179,7 @@ static struct pipe *parse_stream(char **pstring,
                 case '\\':
                         if (next == EOF) {
                                 syntax_error("\\<eof>");
-                                goto parse_error;
+                                xfunc_die();
                         }
                         o_addchr(&dest, '\\');
                         ch = i_getch(input);
@@ -5205,7 +5202,7 @@ static struct pipe *parse_stream(char **pstring,
                                 ch = i_getch(input);
                                 if (ch == EOF) {
                                         syntax_error_unterm_ch('\'');
-                                        goto parse_error;
+                                        /*xfunc_die(); - redundant */
                                 }
                                 nommu_addchr(&ctx.as_string, ch);
                                 if (ch == '\'')
@@ -5232,8 +5229,7 @@ static struct pipe *parse_stream(char **pstring,
 #if !BB_MMU
                         pos = dest.length;
 #endif
-                        if (add_till_backquote(&dest, input))
-                                goto parse_error;
+                        add_till_backquote(&dest, input);
 #if !BB_MMU
                         o_addstr(&ctx.as_string, dest.data + pos);
                         o_addchr(&ctx.as_string, '`');
@@ -5976,7 +5972,8 @@ static int builtin_cd(char **argv)
         const char *newdir = argv[1];
         if (newdir == NULL) {
                 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
-                 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
+                 * bash says "bash: cd: HOME not set" and does nothing
+                 * (exitcode 1)
                  */
                 newdir = getenv("HOME") ? : "/";
         }
@@ -6024,14 +6021,42 @@ static int builtin_exit(char **argv)
 static int builtin_export(char **argv)
 {
         if (*++argv == NULL) {
-                // TODO:
-                // ash emits: export VAR='VAL'
-                // bash: declare -x VAR="VAL"
-                // (both also escape as needed (quotes, $, etc))
                 char **e = environ;
-                if (e)
-                        while (*e)
+                if (e) {
+                        while (*e) {
+#if 0
                                 puts(*e++);
+#else
+                                /* ash emits: export VAR='VAL'
+                                 * bash: declare -x VAR="VAL"
+                                 * we follow ash example */
+                                const char *s = *e++;
+                                const char *p = strchr(s, '=');
+
+                                if (!p) /* wtf? take next variable */
+                                        continue;
+                                /* export var= */
+                                printf("export %.*s", (int)(p - s) + 1, s);
+                                s = p + 1;
+                                while (*s) {
+                                        if (*s != '\'') {
+                                                p = strchrnul(s, '\'');
+                                                /* print 'xxxx' */
+                                                printf("'%.*s'", (int)(p - s), s);
+                                                if (*p == '\0')
+                                                        break;
+                                                s = p;
+                                        }
+                                        /* s points to '; print ''...'''" */
+                                        putchar('"');
+                                        do putchar('\''); while (*++s == '\'');
+                                        putchar('"');
+                                }
+                                putchar('\n');
+#endif
+                        }
+                        fflush(stdout);
+                }
                 return EXIT_SUCCESS;
         }
 
diff --git a/shell/hush_test/hush-misc/export.right b/shell/hush_test/hush-misc/export.right
new file mode 100644
index 000000000..4df2e3858
--- /dev/null
+++ b/shell/hush_test/hush-misc/export.right
@@ -0,0 +1,6 @@
+export aaa1="'''"
+export aaa2=
+export aaa3="'''"'abc'
+export aaa4='def'"'''"
+export aaa5="'''"'abc'"'''"'def'"'''"
+Done
diff --git a/shell/hush_test/hush-misc/export.tests b/shell/hush_test/hush-misc/export.tests
new file mode 100755
index 000000000..87a27ecce
--- /dev/null
+++ b/shell/hush_test/hush-misc/export.tests
@@ -0,0 +1,7 @@
+export aaa1="'''"
+export aaa2=""
+export aaa3="'''abc"
+export aaa4="def'''"
+export aaa5="'''abc'''def'''"
+export | grep aaa.=
+echo Done