hush: make expand_vars_to_list() a bit more sane

function                                             old     new   delta
append_str_maybe_ifs_split                             -      64     +64
expand_vars_to_list                                 1167    1139     -28
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/1 up/down: 64/-28)             Total: 36 bytes

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

diff --git a/shell/hush.c b/shell/hush.c
index 92c79b8b6ca4eef6e46e6e9865407ff821c6d536..b738d2fd83693eae76f716e7581c51d33cd9763d 100644 (file)
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -5955,6 +5955,24 @@ 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 *ended_in_ifs, int n,
+       int first_ch, const char *val)
+{
+       if (!(first_ch & 0x80)) { /* unquoted $VAR */
+               debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
+                               !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
+               if (val && val[0])
+                       n = expand_on_ifs(ended_in_ifs, output, n, val);
+       } else { /* quoted "$VAR" */
+               output->has_quoted_part = 1;
+               debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
+                               !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
+               if (val && val[0])
+                       o_addQstr(output, val);
+       }
+       return n;
+}
+
 /* Helper:
  * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
  */
@@ -6290,11 +6308,7 @@ 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;
-               char *to_be_freed = NULL;
                const char *val = NULL;
-#if ENABLE_HUSH_TICK
-               o_string subst_result = NULL_O_STRING;
-#endif
 #if ENABLE_FEATURE_SH_MATH
                char arith_buf[sizeof(arith_t)*3 + 2];
 #endif
@@ -6382,7 +6396,9 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *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> */
                        arg++;
                        /* Can't just stuff it into output o_string,
@@ -6392,8 +6408,10 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
                        G.last_exitcode = process_command_subs(&subst_result, arg);
                        G.expand_exitcode = G.last_exitcode;
                        debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
-                       val = subst_result.data;
-                       goto store_val;
+                       n = append_str_maybe_ifs_split(output, &ended_in_ifs, n, first_ch, subst_result.data);
+                       o_free_unsafe(&subst_result);
+                       goto restore;
+               }
 #endif
 #if ENABLE_FEATURE_SH_MATH
                case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
@@ -6409,37 +6427,23 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
                        break;
                }
 #endif
-               default:
+               default: {
+                       char *to_be_freed;
                        val = expand_one_var(&to_be_freed, arg, &p);
- IF_HUSH_TICK(store_val:)
-                       if (!(first_ch & 0x80)) { /* unquoted $VAR */
-                               debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
-                                               !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
-                               if (val && val[0]) {
-                                       n = expand_on_ifs(&ended_in_ifs, output, n, val);
-                                       val = NULL;
-                               }
-                       } else { /* quoted $VAR, val will be appended below */
-                               output->has_quoted_part = 1;
-                               debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
-                                               !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
-                       }
-                       break;
+                       n = append_str_maybe_ifs_split(output, &ended_in_ifs, n, first_ch, val);
+                       free(to_be_freed);
+                       goto restore;
+               } /* default: */
                } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
 
                if (val && val[0]) {
                        o_addQstr(output, val);
                }
-               free(to_be_freed);
-
+ restore:
                /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
                 * Do the check to avoid writing to a const string. */
                if (*p != SPECIAL_VAR_SYMBOL)
                        *p = SPECIAL_VAR_SYMBOL;
-
-#if ENABLE_HUSH_TICK
-               o_free(&subst_result);
-#endif
                arg = ++p;
        } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */