utf_len declaration is incompatible with definition

[michaelforney]

With HAVE_ANSI_PROTOS, utf_len is declared in funcs.h as

int utf_len(unsigned char ch);

and defined in charset.c as

int utf_len(ch)
	unsigned char ch;
{ ... }

However, according to the C standard (C89 3.5.4.3, C99 6.7.5.3p15),

If one type has a parameter type list and the other type is specified by a function definition that contains a (possibly empty) identifier list, both shall agree in the number of parameters, and the type of each prototype parameter shall be compatible with the type that results from the application of the default argument promotions to the type of the corresponding identifier.

Since int can represent all the values of unsigned char, ch gets promoted to int by default argument promotions. unsigned char is not compatible with int, making the two function types incompatible.

To fix this, the prototype declaration in funcs.h needs to be updated to int utf_len(int ch). However, since these declarations are autogenerated from the definitions, it is probably easier to resolve by just changing the type in the definition from unsigned char to int.

This same issue also affects pappend and set_status_col in line.c.