hush: consolidate handling of setting/unsetting of PSn, LINENO, OPTIND

function                                             old     new   delta
handle_changed_special_names                           -      99     +99
unset_local_var                                      256     155    -101
set_local_var                                        557     437    -120
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/2 up/down: 99/-221)          Total: -122 bytes

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

1 files changed, 30 insertions, 29 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 9ea3e3fcb..7b59b0ff9 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -2123,6 +2123,27 @@ static const char* FAST_FUNC get_local_var_value(const char *name)
         return NULL;
 }
 
+static void handle_changed_special_names(const char *name, unsigned name_len)
+{
+        if (name_len == 3 && name[0] == 'P' && name[1] == 'S') {
+                cmdedit_update_prompt();
+                return;
+        }
+
+        if ((ENABLE_HUSH_LINENO_VAR || ENABLE_HUSH_GETOPTS)
+         && name_len == 6
+        ) {
+#if ENABLE_HUSH_LINENO_VAR
+                if (strncmp(name, "LINENO", 6) == 0)
+                        G.lineno_var = NULL;
+#endif
+#if ENABLE_HUSH_GETOPTS
+                if (strncmp(name, "OPTIND", 6) == 0)
+                        G.getopt_count = 0;
+#endif
+        }
+}
+
 /* str holds "NAME=VAL" and is expected to be malloced.
  * We take ownership of it.
  */
@@ -2264,21 +2285,7 @@ static int set_local_var(char *str, unsigned flags)
         }
         free(free_me);
 
-        /* Handle special names */
-        if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
-                cmdedit_update_prompt();
-        else
-        if ((ENABLE_HUSH_LINENO_VAR || ENABLE_HUSH_GETOPTS) && name_len == 7) {
-#if ENABLE_HUSH_LINENO_VAR
-                if (G.lineno_var && strncmp(cur->varstr, "LINENO", 6) == 0)
-                        G.lineno_var = NULL;
-#endif
-#if ENABLE_HUSH_GETOPTS
-                /* defoptindvar is a "OPTIND=..." constant string */
-                if (strncmp(cur->varstr, defoptindvar, 7) == 0)
-                        G.getopt_count = 0;
-#endif
-        }
+        handle_changed_special_names(cur->varstr, name_len - 1);
 
         return 0;
 }
@@ -2297,32 +2304,26 @@ static int unset_local_var_len(const char *name, int name_len)
         if (!name)
                 return EXIT_SUCCESS;
 
-        if ((ENABLE_HUSH_LINENO_VAR || ENABLE_HUSH_GETOPTS) && name_len == 6) {
-#if ENABLE_HUSH_GETOPTS
-                if (strncmp(name, "OPTIND", 6) == 0)
-                        G.getopt_count = 0;
-#endif
-#if ENABLE_HUSH_LINENO_VAR
-                if (G.lineno_var && strncmp(name, "LINENO", 6) == 0)
-                        G.lineno_var = NULL;
-#endif
-        }
-
         cur_pp = &G.top_var;
         while ((cur = *cur_pp) != NULL) {
-                if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
+                if (strncmp(cur->varstr, name, name_len) == 0
+                 && cur->varstr[name_len] == '='
+                ) {
                         if (cur->flg_read_only) {
                                 bb_error_msg("%s: readonly variable", name);
                                 return EXIT_FAILURE;
                         }
+
                         *cur_pp = cur->next;
                         debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
                         bb_unsetenv(cur->varstr);
-                        if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
-                                cmdedit_update_prompt();
+
+                        handle_changed_special_names(name, name_len);
+
                         if (!cur->max_len)
                                 free(cur->varstr);
                         free(cur);
+
                         return EXIT_SUCCESS;
                 }
                 cur_pp = &cur->next;