[perl #31697] [PATCH] B::Showlex::newlex enhancement and pod

[p5sagit/p5-mst-13.2.git] / pp_sys.c

diff --git a/pp_sys.c b/pp_sys.c
index 4432a47..3071f1b 100644 (file)
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -15,6 +15,15 @@
  * a rumour and a trouble as of great engines throbbing and labouring.
  */
 
+/* This file contains system pp ("push/pop") functions that
+ * execute the opcodes that make up a perl program. A typical pp function
+ * expects to find its arguments on the stack, and usually pushes its
+ * results onto the stack, hence the 'pp' terminology. Each OP structure
+ * contains a pointer to the relevant pp_foo() function.
+ *
+ * By 'system', we mean ops which interact with the OS, such as pp_open().
+ */
+
 #include "EXTERN.h"
 #define PERL_IN_PP_SYS_C
 #include "perl.h"
@@ -1656,7 +1665,10 @@ PP(pp_sysread)
     }
     if (DO_UTF8(bufsv)) {
        /* convert offset-as-chars to offset-as-bytes */
-       offset = utf8_hop((U8 *)buffer,offset) - (U8 *) buffer;
+       if (offset >= (int)blen)
+           offset += SvCUR(bufsv) - blen;
+       else
+           offset = utf8_hop((U8 *)buffer,offset) - (U8 *) buffer;
     }
  more_bytes:
     bufsize = SvCUR(bufsv);