commit 6409553b6e3b4de4e1d72b8ee5445595214581ff
author Yegappan Lakshmanan <yegappan@yahoo.com> Mon Dec 06 11:03:55 2021 +0000
committer Bram Moolenaar <Bram@vim.org> Mon Dec 06 11:03:55 2021 +0000
tree 1b24d5f956763a1bc7a5b47fc9875598d0d438d6
parent 40bcec1bac34d34a3d4d7c5f6b2cc1f163acbd00

patch 8.2.3751: cannot assign a lambda to an option that takes a function

Problem:    Cannot assign a lambda to an option that takes a function.
Solution:   Automatically convert the lambda to a string. (Yegappan
            Lakshmanan, closes #9286)

src/evalvars.c

diff --git a/src/evalvars.c b/src/evalvars.c
index 4342100..f5465cf 100644
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -1367,7 +1367,7 @@
     char_u	*op)
 {
     char_u	*p;
-    int		opt_flags;
+    int		scope;
     char_u	*arg_end = NULL;
 
     if ((flags & (ASSIGN_CONST | ASSIGN_FINAL))
@@ -1378,7 +1378,7 @@
     }
 
     // Find the end of the name.
-    p = find_option_end(&arg, &opt_flags);
+    p = find_option_end(&arg, &scope);
     if (p == NULL || (endchars != NULL
 			       && vim_strchr(endchars, *skipwhite(p)) == NULL))
 	emsg(_(e_unexpected_characters_in_let));
@@ -1391,11 +1391,14 @@
 	char_u	    *stringval = NULL;
 	char_u	    *s = NULL;
 	int	    failed = FALSE;
+	int	    opt_p_flags;
+	char_u	    *tofree = NULL;
 
 	c1 = *p;
 	*p = NUL;
 
-	opt_type = get_option_value(arg, &numval, &stringval, opt_flags);
+	opt_type = get_option_value(arg, &numval, &stringval, &opt_p_flags,
+									scope);
 	if ((opt_type == gov_bool
 		    || opt_type == gov_number
 		    || opt_type == gov_hidden_bool
@@ -1410,9 +1413,20 @@
 		n = (long)tv_get_number(tv);
 	}
 
+	if (opt_p_flags & P_FUNC && (tv->v_type == VAR_PARTIAL
+						|| tv->v_type == VAR_FUNC))
+	{
+	    char_u	numbuf[NUMBUFLEN];
+
+	    // If the option can be set to a function reference or a lambda
+	    // and the passed value is a function reference, then convert it to
+	    // the name (string) of the function reference.
+
+	    s = tv2string(tv, &tofree, numbuf, 0);
+	}
 	// Avoid setting a string option to the text "v:false" or similar.
 	// In Vim9 script also don't convert a number to string.
-	if (tv->v_type != VAR_BOOL && tv->v_type != VAR_SPECIAL
+	else if (tv->v_type != VAR_BOOL && tv->v_type != VAR_SPECIAL
 			 && (!in_vim9script() || tv->v_type != VAR_NUMBER))
 	    s = tv_get_string_chk(tv);
 
@@ -1458,7 +1472,7 @@
 	{
 	    if (opt_type != gov_string || s != NULL)
 	    {
-		set_option_value(arg, n, s, opt_flags);
+		set_option_value(arg, n, s, scope);
 		arg_end = p;
 	    }
 	    else
@@ -1466,6 +1480,7 @@
 	}
 	*p = c1;
 	vim_free(stringval);
+	vim_free(tofree);
     }
     return arg_end;
 }