sv_Replace issue

[llde]

From QQuix post:

Investigating a report from forli, I’ve found something weird with sv_replace related to replacing %’s:

let s := ">> 0%%<<"
sv_Replace " 0%%%%|OO" s
print s ; OK – prints “>>OO<<”
printc $s ; OK – prints “>>OO<<”

but
let s := ">> 0%%<<"
sv_Replace " 0%%|OO" s
print s ; prints “>>OO<<”
printc $s ; ERROR “Too few args for format specifier”

Since it complained about too few args, I tried adding a dummy arg and it did not throw the error
printc $s 99 ; prints “>>OO<<”

But the result shouldn’t be “>>OO%<<”? ( as the last pair of % should be joined in a single % and not replaced)

The same problem occurs with sv_construct and MessageBoxEX.

My feeling is that, in the second example, sv_replace leaves an unprintable something in the string which Print does not care about, but commands that uses format strings do not like.