Integrate from maint-5.8 : changes 18290-1, 18293-5, 18297

p4raw-id: //depot/perl@18299
p4raw-integrated: from //depot/maint-5.8/perl@18298 'copy in'
	pod/perlretut.pod (@17645..) pod/perlre.pod (@18080..)
	ext/POSIX/t/is.t (@18189..) t/op/subst.t (@18214..)
	ext/POSIX/t/posix.t (@18271..) t/op/pat.t (@18276..)
	ext/POSIX/POSIX.pod (@18294..) 'merge in' regexec.c (@18095..)

2 files changed, 64 insertions, 5 deletions

diff --git a/t/op/pat.t b/t/op/pat.t
index 20763e4ef9..62520dda6b 100755
--- a/t/op/pat.t
+++ b/t/op/pat.t
@@ -6,7 +6,7 @@
 
 $| = 1;
 
-print "1..942\n";
+print "1..968\n";
 
 BEGIN {
     chdir 't' if -d 't';
@@ -3006,4 +3006,53 @@ print "\x{072F}" =~ /\P{Syriac1}/ ? "ok $test\n" : "not ok $test\n"; $test++;
     ++$test;
 }
 
-# last test 942
+{
+    print "# [perl #15763]\n";
+
+    $a = "x\x{100}";
+    chop $a; # but leaves the UTF-8 flag
+    $a .= "y"; # 1 byte before "y"
+
+    ok($a =~ /^\C/,      'match one \C on 1-byte UTF-8');
+    ok($a =~ /^\C{1}/,   'match \C{1}');
+
+    ok($a =~ /^\Cy/,      'match \Cy');
+    ok($a =~ /^\C{1}y/,   'match \C{1}y');
+
+    $a = "\x{100}y"; # 2 bytes before "y"
+
+    ok($a =~ /^\C/,       'match one \C on 2-byte UTF-8');
+    ok($a =~ /^\C{1}/,    'match \C{1}');
+    ok($a =~ /^\C\C/,     'match two \C');
+    ok($a =~ /^\C{2}/,    'match \C{2}');
+
+    ok($a =~ /^\C\C\C/,    'match three \C on 2-byte UTF-8 and a byte');
+    ok($a =~ /^\C{3}/,     'match \C{3}');
+
+    ok($a =~ /^\C\Cy/,     'match two \C');
+    ok($a =~ /^\C{2}y/,    'match \C{2}');
+
+    ok($a !~ /^\C\C\Cy/,    'not match three \Cy');
+    ok($a !~ /^\C{2}\Cy/,   'not match \C{3}y');
+
+    $a = "\x{1000}y"; # 3 bytes before "y"
+
+    ok($a =~ /^\C/,         'match one \C on three-byte UTF-8');
+    ok($a =~ /^\C{1}/,      'match \C{1}');
+    ok($a =~ /^\C\C/,       'match two \C');
+    ok($a =~ /^\C{2}/,      'match \C{2}');
+    ok($a =~ /^\C\C\C/,     'match three \C');
+    ok($a =~ /^\C{3}/,      'match \C{3}');
+
+    ok($a =~ /^\C\C\C\C/,   'match four \C on three-byte UTF-8 and a byte');
+    ok($a =~ /^\C{4}/,      'match \C{4}');
+
+    ok($a =~ /^\C\C\Cy/,    'match three \Cy');
+    ok($a =~ /^\C{3}y/,     'match \C{3}y');
+
+    ok($a !~ /^\C\C\C\C\y/, 'not match four \Cy');
+    ok($a !~ /^\C{4}y/,     'not match \C{4}y');
+}
+
+# last test 968
+
diff --git a/t/op/subst.t b/t/op/subst.t
index ef0ae0a064..797f24139b 100755
--- a/t/op/subst.t
+++ b/t/op/subst.t
@@ -7,7 +7,7 @@ BEGIN {
 }
 
 require './test.pl';
-plan( tests => 124 );
+plan( tests => 125 );
 
 $x = 'foo';
 $_ = "x";
@@ -494,9 +494,19 @@ SKIP: {
 $_ = 'aaaa';
 $r = 'x';
 $s = s/a(?{})/$r/g;
-is("<$_> <$s>", "<xxxx> <4>", "perl #7806");
+is("<$_> <$s>", "<xxxx> <4>", "[perl #7806]");
 
 $_ = 'aaaa';
 $s = s/a(?{})//g;
-is("<$_> <$s>", "<> <4>", "perl #7806");
+is("<$_> <$s>", "<> <4>", "[perl #7806]");
 
+# [perl #19048] Coredump in silly replacement
+{
+    local $^W = 0;
+    $_="abcdef\n";
+    s!.!!eg;
+    is($_, "\n", "[perl #19048]");
+}
+
+
+