restrict \p{IsUserDefined} to In\w+ and In\w+

In L<perlunicode/"User-Defined Character Properties">, it says you can
create custom properties by defining subroutines whose names begin with
"In" or "Is". However, perl doesn't actually enforce that naming
restriction, so \p{foo::bar} will call foo::Bar() if it exists.

This commit finally enforces this convention. Note that this broke a
number of existing tests for properties, since they didn't always use an
Is/In prefix.
(cherry picked from commit d658a8a81c4f311bef688fd51df924a424429f14)

3 files changed, 22 insertions, 16 deletions

diff --git a/lib/utf8_heavy.pl b/lib/utf8_heavy.pl
index 250eb69f05..d473dd2a42 100644
--- a/lib/utf8_heavy.pl
+++ b/lib/utf8_heavy.pl
@@ -83,7 +83,7 @@ sub croak { require Carp; Carp::croak(@_) }
 
                 my $caller1 = $type =~ s/(.+)::// ? $1 : caller(1);
 
-                if (defined $caller1 && $type =~ /^(?:\w+)$/) {
+                if (defined $caller1 && $type =~ /^I[ns]\w+$/) {
                     my $prop = "${caller1}::$type";
                     if (exists &{$prop}) {
                         no strict 'refs';
diff --git a/t/re/regexp_unicode_prop.t b/t/re/regexp_unicode_prop.t
index ba55b96115..e2c0c51d6f 100644
--- a/t/re/regexp_unicode_prop.t
+++ b/t/re/regexp_unicode_prop.t
@@ -88,14 +88,13 @@ my @USER_DEFINED_PROPERTIES = (
    InNotKana                 => ['\x{3040}', '!\x{3041}'],
    InConsonant               => ['d',        '!e'],
    IsSyriac1                 => ['\x{0712}', '!\x{072F}'],
-   Syriac1                   => ['\x{0712}', '!\x{072F}'],
    '# User-defined character properties my lack \n at the end',
    InGreekSmall              => ['\N{GREEK SMALL LETTER PI}',
                                  '\N{GREEK SMALL LETTER FINAL SIGMA}'],
    InGreekCapital            => ['\N{GREEK CAPITAL LETTER PI}', '!\x{03A2}'],
    Dash                      => ['-'],
    ASCII_Hex_Digit           => ['!-', 'A'],
-   AsciiHexAndDash           => ['-', 'A'],
+   IsAsciiHexAndDash         => ['-', 'A'],
 );
 
 
@@ -118,7 +117,8 @@ my %SHORT_PROPERTIES = (
 #
 # Illegal properties
 #
-my @ILLEGAL_PROPERTIES = qw [q qrst];
+my @ILLEGAL_PROPERTIES =
+    qw[q qrst f foo isfoo infoo ISfoo INfoo Is::foo In::foo];
 
 my %d;
 
@@ -288,17 +288,23 @@ sub IsSyriac1 {<<'--'}
 0730    074A
 --
 
-sub Syriac1 {<<'--'}
-0712    072C
-0730    074A
---
-
 sub InGreekSmall   {return "03B1\t03C9"}
 sub InGreekCapital {return "0391\t03A9\n-03A2"}
 
-sub AsciiHexAndDash {<<'--'}
+sub IsAsciiHexAndDash {<<'--'}
 +utf8::ASCII_Hex_Digit
 +utf8::Dash
 --
 
+# fake user-defined properties; these subs shouldn't be called, because
+# their names don't start with In or Is
+
+sub f       { die }
+sub foo     { die }
+sub isfoo   { die }
+sub infoo   { die }
+sub ISfoo   { die }
+sub INfoo   { die }
+sub Is::foo { die }
+sub In::foo { die }
 __END__
diff --git a/t/uni/class.t b/t/uni/class.t
index 3dde5082cb..92f215f411 100644
--- a/t/uni/class.t
+++ b/t/uni/class.t
@@ -6,13 +6,13 @@ BEGIN {
 
 plan tests => 10;
 
-sub MyUniClass {
+sub IsMyUniClass {
   <<END;
 0030	004F
 END
 }
 
-sub Other::Class {
+sub Other::IsClass {
   <<END;
 0040	005F
 END
@@ -20,8 +20,8 @@ END
 
 sub A::B::Intersection {
   <<END;
-+main::MyUniClass
-&Other::Class
++main::IsMyUniClass
+&Other::IsClass
 END
 }
 
@@ -63,10 +63,10 @@ is(($str =~ /(\p{Letter}+)/)[0], 'ABCDEFGHIJKLMNOPQRSTUVWXYZ');
 is(($str =~ /(\p{l}+)/)[0], 'ABCDEFGHIJKLMNOPQRSTUVWXYZ');
 
 # make sure it finds user-defined class
-is(($str =~ /(\p{MyUniClass}+)/)[0], '0123456789:;<=>?@ABCDEFGHIJKLMNO');
+is(($str =~ /(\p{IsMyUniClass}+)/)[0], '0123456789:;<=>?@ABCDEFGHIJKLMNO');
 
 # make sure it finds class in other package
-is(($str =~ /(\p{Other::Class}+)/)[0], '@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_');
+is(($str =~ /(\p{Other::IsClass}+)/)[0], '@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_');
 
 # make sure it finds class in other OTHER package
 is(($str =~ /(\p{A::B::Intersection}+)/)[0], '@ABCDEFGHIJKLMNO');