hush: remove pointless "next" var, simplify expand_vars_to_list()

function                                             old     new   delta
o_addstr                                               -      26     +26
expand_vars_to_list                                 1112    1117      +5
encode_then_expand_vararg                            398     382     -16
parse_dollar                                         779     762     -17
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/2 up/down: 31/-33)             Total: -2 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 16 insertions, 19 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 2d4e3fa66..fca67dc17 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -475,6 +475,7 @@
 #endif
 
 #define SPECIAL_VAR_SYMBOL_STR "\3"
+#define SPECIAL_VAR_SYMBOL_CHR '\3'
 #define SPECIAL_VAR_SYMBOL       3
 /* The "variable" with name "\1" emits string "\3". Testcase: "echo ^C" */
 #define SPECIAL_VAR_QUOTED_SVS   1
@@ -5797,7 +5798,6 @@ static char *encode_then_expand_vararg(const char *str, int handle_squotes, int
 
         for (;;) {
                 int ch;
-                int next;
 
                 ch = i_getch(&input);
                 if (ch == EOF) {
@@ -5837,10 +5837,6 @@ static char *encode_then_expand_vararg(const char *str, int handle_squotes, int
                         o_addqchr(&dest, ch);
                         continue;
                 }
-                next = '\0';
-                if (ch != '\n') {
-                        next = i_peek(&input);
-                }
                 if (ch == '$') {
                         if (!parse_dollar(NULL, &dest, &input, /*quote_mask:*/ 0x80)) {
                                 debug_printf_parse("%s: error: parse_dollar returned 0 (error)\n", __func__);
@@ -5956,7 +5952,7 @@ static char *replace_pattern(char *val, const char *pattern, const char *repl, c
 #endif /* BASH_PATTERN_SUBST */
 
 static int append_str_maybe_ifs_split(o_string *output, int n,
-        int first_ch, const char *val)
+                int first_ch, const char *val)
 {
         if (!(first_ch & 0x80)) { /* unquoted $VAR */
                 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
@@ -6348,7 +6344,6 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
 
         while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
                 char first_ch;
-                const char *val = NULL;
 #if ENABLE_FEATURE_SH_MATH
                 char arith_buf[sizeof(arith_t)*3 + 2];
 #endif
@@ -6424,19 +6419,23 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
                         }
                         break;
                 }
-                case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
+                case SPECIAL_VAR_SYMBOL: {
+                        /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
                         /* "Empty variable", used to make "" etc to not disappear */
                         output->has_quoted_part = 1;
-                        arg++;
                         cant_be_null = 0x80;
+                        arg++;
                         break;
+                }
                 case SPECIAL_VAR_QUOTED_SVS:
                         /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_QUOTED_SVS><SPECIAL_VAR_SYMBOL> */
+                        /* "^C variable", represents literal ^C char (possible in scripts) */
+                        o_addchr(output, SPECIAL_VAR_SYMBOL_CHR);
                         arg++;
-                        val = SPECIAL_VAR_SYMBOL_STR;
                         break;
 #if ENABLE_HUSH_TICK
-                case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
+                case '`': {
+                        /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
                         o_string subst_result = NULL_O_STRING;
 
                         *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
@@ -6450,11 +6449,12 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
                         debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
                         n = append_str_maybe_ifs_split(output, n, first_ch, subst_result.data);
                         o_free_unsafe(&subst_result);
-                        goto restore;
+                        break;
                 }
 #endif
 #if ENABLE_FEATURE_SH_MATH
-                case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
+                case '+': {
+                        /* <SPECIAL_VAR_SYMBOL>+arith<SPECIAL_VAR_SYMBOL> */
                         arith_t res;
 
                         arg++; /* skip '+' */
@@ -6463,19 +6463,16 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
                         res = expand_and_evaluate_arith(arg, NULL);
                         debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
                         sprintf(arith_buf, ARITH_FMT, res);
-                        val = arith_buf;
+                        o_addstr(output, arith_buf);
                         break;
                 }
 #endif
                 default:
+                        /* <SPECIAL_VAR_SYMBOL>varname[ops]<SPECIAL_VAR_SYMBOL> */
                         n = expand_one_var(output, n, first_ch, arg, &p);
-                        goto restore;
+                        break;
                 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
 
-                if (val && val[0]) {
-                        o_addQstr(output, val);
-                }
- restore:
                 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
                  * Do the check to avoid writing to a const string. */
                 if (*p != SPECIAL_VAR_SYMBOL)