grep: simplify data movement slightly

* src/grep.c (fillbuf): Simplify movement of saved data.

1 files changed, 5 insertions, 11 deletions

diff --git a/src/grep.c b/src/grep.c
index f86bce55..271b6b98 100644
--- a/src/grep.c
+++ b/src/grep.c
@@ -943,15 +943,8 @@ fillbuf (size_t save, struct stat const *st)
   char *readbuf;
   size_t readsize;
 
-  /* Offset from start of buffer to start of old stuff
-     that we want to save.  */
-  size_t saved_offset = buflim - save - buffer;
-
   if (pagesize <= buffer + bufalloc - sizeof (uword) - buflim)
-    {
-      readbuf = buflim;
-      bufbeg = buflim - save;
-    }
+    readbuf = buflim;
   else
     {
       size_t minsize = save + pagesize;
@@ -989,9 +982,8 @@ fillbuf (size_t save, struct stat const *st)
 
       newbuf = bufalloc < newalloc ? xmalloc (bufalloc = newalloc) : buffer;
       readbuf = ALIGN_TO (newbuf + 1 + save, pagesize);
-      bufbeg = readbuf - save;
-      memmove (bufbeg, buffer + saved_offset, save);
-      bufbeg[-1] = eolbyte;
+      size_t moved = save + 1;  /* Move the preceding byte sentinel too.  */
+      memmove (readbuf - moved, buflim - moved, moved);
       if (newbuf != buffer)
         {
           free (buffer);
@@ -999,6 +991,8 @@ fillbuf (size_t save, struct stat const *st)
         }
     }
 
+  bufbeg = readbuf - save;
+
   clear_asan_poison ();
 
   readsize = buffer + bufalloc - sizeof (uword) - readbuf;