[icu-design] Proposed API change to Unicode Spoof Detection

[Andy H. <and...@gm...>]

I am proposing a small change to the USpoofChecker API.

In the function

U_DRAFT int32_t U_EXPORT2
uspoof_areConfusableUTF8(const USpoofChecker *sc,
                         const char *s1, int32_t length1,
                         const char *s2, int32_t length2,
                         int32_t *position,
                         UErrorCode *status);


I propose eliminating the "position" parameter.

This parameter turns out to serve no useful purpose.  In other spoof
checking functions, the corresponding "position" parameter returns the
position of a detected problem with the identifier being checked.  For
this function, we are testing whether two complete identifiers are
potentially visually confusable.  There is no specific position in
them that causes them to be confusable - they must be confusable at
all positions for there to be a problem.

Since this is a new API, there are no compatibility issues with
removing the parameter.

The same change is needed in uspoof_areConfusableUTF8() and
uspoof_areConfusableUnicodeString()