refactor(option.c): factor out option prefix parsing

1 files changed, 13 insertions, 7 deletions

diff --git a/src/nvim/option.c b/src/nvim/option.c
index c511a8e622..a54dd4d877 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -1179,19 +1179,25 @@ static set_op_T get_op(const char *arg)
   return op;
 }
 
-static void do_set_option(int opt_flags, char **argp, bool *did_show, char *errbuf,
-                          size_t errbuflen, char **errmsg)
+static int get_option_prefix(char **argp)
 {
-  int prefix = 1;  // 1: nothing, 0: "no", 2: "inv" in front of name
-
   if (strncmp(*argp, "no", 2) == 0) {
-    prefix = 0;
     *argp += 2;
+    return 0;
   } else if (strncmp(*argp, "inv", 3) == 0) {
-    prefix = 2;
     *argp += 3;
+    return 2;
   }
 
+  return 1;
+}
+
+static void do_set_option(int opt_flags, char **argp, bool *did_show, char *errbuf,
+                          size_t errbuflen, char **errmsg)
+{
+  // 1: nothing, 0: "no", 2: "inv" in front of name
+  int prefix = get_option_prefix(argp);
+
   char *arg = *argp;
 
   // find end of name
@@ -1221,11 +1227,11 @@ static void do_set_option(int opt_flags, char **argp, bool *did_show, char *errb
       key = find_key_option(arg + 1, true);
     }
   } else {
-    len = 0;
     // The two characters after "t_" may not be alphanumeric.
     if (arg[0] == 't' && arg[1] == '_' && arg[2] && arg[3]) {
       len = 4;
     } else {
+      len = 0;
       while (ASCII_ISALNUM(arg[len]) || arg[len] == '_') {
         len++;
       }