Suppress useless memmove() when buffer already contains left-justified

data.

diff --git a/src/interfaces/libpq/fe-misc.c b/src/interfaces/libpq/fe-misc.c
index 1750166..04be4bb 100644 (file)
--- a/src/interfaces/libpq/fe-misc.c
+++ b/src/interfaces/libpq/fe-misc.c
@@ -25,7 +25,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-misc.c,v 1.48 2001/03/31 23:13:30 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-misc.c,v 1.49 2001/05/28 15:29:51 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -400,14 +400,20 @@ pqReadData(PGconn *conn)
        /* Left-justify any data in the buffer to make room */
        if (conn->inStart < conn->inEnd)
        {
-               memmove(conn->inBuffer, conn->inBuffer + conn->inStart,
-                               conn->inEnd - conn->inStart);
-               conn->inEnd -= conn->inStart;
-               conn->inCursor -= conn->inStart;
-               conn->inStart = 0;
+               if (conn->inStart > 0)
+               {
+                       memmove(conn->inBuffer, conn->inBuffer + conn->inStart,
+                                       conn->inEnd - conn->inStart);
+                       conn->inEnd -= conn->inStart;
+                       conn->inCursor -= conn->inStart;
+                       conn->inStart = 0;
+               }
        }
        else
+       {
+               /* buffer is logically empty, reset it */
                conn->inStart = conn->inCursor = conn->inEnd = 0;
+       }
 
        /*
         * If the buffer is fairly full, enlarge it. We need to be able to