From 90f6536b6e4fefdbe12a64f4201c9f73580aab88 Mon Sep 17 00:00:00 2001
From: Tony Cook <tony@develop-help.com>
Date: Sat, 17 Mar 2012 01:10:36 +1100
Subject: [PATCH] fix a fencepost error I found trying to fall asleep

---
 sv.c        | 5 +++--
 t/io/utf8.t | 5 ++++-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/sv.c b/sv.c
index 78eeddd..e2bed05 100644
--- a/sv.c
+++ b/sv.c
@@ -7719,10 +7719,11 @@ S_sv_gets_read_record(pTHX_ SV *const sv, PerlIO *const fp, I32 append)
 		    }
 		}
 
-		if (!charstart) {
+		if (charcount < recsize) {
 		    /* read the rest of the current character, and maybe the
 		       beginning of the next, if we need it */
-		    STRLEN readsize = skip - (bend - bufp) + (charcount + 1 < recsize);
+		    STRLEN readsize = (charstart ? 0 : skip - (bend - bufp))
+			+ (charcount + 1 < recsize);
 		    STRLEN bufp_offset = bufp - buffer;
 		    SSize_t morebytesread;
 
diff --git a/t/io/utf8.t b/t/io/utf8.t
index ed535a3..919b734 100644
--- a/t/io/utf8.t
+++ b/t/io/utf8.t
@@ -10,7 +10,7 @@ BEGIN {
 no utf8; # needed for use utf8 not griping about the raw octets
 
 
-plan(tests => 58);
+plan(tests => 59);
 
 $| = 1;
 
@@ -354,6 +354,7 @@ is($failed, undef);
     open F, ">:utf8", $a_file;
     print F "foo\xE4";
     print F "bar\xFE";
+    print F "a\xE4a";
     close F;
     open F, "<:utf8", $a_file;
     local $/ = \4;
@@ -361,6 +362,8 @@ is($failed, undef);
     is($line, "foo\xE4", "readline with \$/ = \\4");
     $line .= <F>;
     is($line, "foo\xE4bar\xFE", "rcatline with \$/ = \\4");
+    $line = <F>;
+    is($line, "a\xE4a", "readline with boundary condition");
     close F;
 
     # badly encoded at EOF
-- 
2.7.4