Restructure < 7.4 protocol code a bit.

This avoids accessing unitialized bitmap[0]. It was harmless, as the
uninitialize value that was read was not used for anything, but Coverity
complained about it.

diff --git a/qresult.c b/qresult.c
index 8ca59595591afa4c45ef4973f87ed7e988d71e19..d791ed38a0f202cf7b0b7ef7c3c6358ac4642e16 100644 (file)
--- a/qresult.c
+++ b/qresult.c
@@ -1523,10 +1523,6 @@ QR_read_a_tuple_from_db(QResultClass *self, char binary)
        this_keyset->status = 0;
    }
 
-   bitmaplen = (Int2) ci_num_fields / BYTELEN;
-   if ((ci_num_fields % BYTELEN) > 0)
-       bitmaplen++;
-
    /*
     * At first the server sends a bitmap that indicates which database
     * fields are null
@@ -1540,45 +1536,72 @@ else
 {inolog("%dth record in key numf=%d\n", self->num_cached_keys, numf);}
    }
    else
+   {
+       bitmaplen = (Int2) ci_num_fields / BYTELEN;
+       if ((ci_num_fields % BYTELEN) > 0)
+           bitmaplen++;
+
        SOCK_get_n_char(sock, bitmap, bitmaplen);
 
+       bitmap_pos = 0;
+       bitcnt = 0;
+       bmp = bitmap[bitmap_pos];
+   }
 
-   bitmap_pos = 0;
-   bitcnt = 0;
-   bmp = bitmap[bitmap_pos];
    flds = self->fields;
 
    for (field_lf = 0; field_lf < ci_num_fields; field_lf++)
    {
-       /* Check if the current field is NULL */
-       if (!PROTOCOL_74(ci) && (!(bmp & 0200)))
+       BOOL isnull = FALSE;
+
+       if (!PROTOCOL_74(ci))
+       {
+           isnull = ((bmp & 0200) == 0);
+           /* move to next bit in the bitmap */
+           bitcnt++;
+           if (BYTELEN == bitcnt)
+           {
+               bitmap_pos++;
+               bmp = bitmap[bitmap_pos];
+               bitcnt = 0;
+           }
+           else
+               bmp <<= 1;
+
+           if (!isnull)
+           {
+               /* get the length of the field (four bytes) */
+               len = SOCK_get_int(sock, sizeof(Int4));
+
+               /*
+                * In the old protocol version, the length
+                * field of an AsciiRow message includes the
+                * 4-byte length field itself, while the
+                * length field in the BinaryRow does not.
+                */
+               if (!binary)
+                   len -= sizeof(Int4);
+           }
+       }
+       else
+       {
+           /* get the length of the field (four bytes) */
+           len = SOCK_get_int(sock, sizeof(Int4));
+
+           /* -1 means NULL */
+           if (len < 0)
+               isnull = TRUE;
+
+       }
+
+       if (isnull)
        {
-           /* YES, it is NULL ! */
            this_tuplefield[field_lf].len = 0;
            this_tuplefield[field_lf].value = 0;
+           continue;
        }
        else
        {
-           /*
-            * NO, the field is not null. so get at first the length of
-            * the field (four bytes)
-            */
-           len = SOCK_get_int(sock, VARHDRSZ);
-inolog("QR_read_a_tuple_from_db len=%d\n", len);
-           if (PROTOCOL_74(ci))
-           {
-               if (len < 0)
-               {
-                   /* YES, it is NULL ! */
-                   this_tuplefield[field_lf].len = 0;
-                   this_tuplefield[field_lf].value = 0;
-                   continue;
-               }
-           }
-           else
-           if (!binary)
-               len -= VARHDRSZ;
-
            if (field_lf >= effective_cols)
                buffer = tidoidbuf;
            else
@@ -1616,19 +1639,6 @@ inolog("QR_read_a_tuple_from_db len=%d\n", len);
                    CI_get_display_size(flds, field_lf) = len;
            }
        }
-
-       /*
-        * Now adjust for the next bit to be scanned in the next loop.
-        */
-       bitcnt++;
-       if (BYTELEN == bitcnt)
-       {
-           bitmap_pos++;
-           bmp = bitmap[bitmap_pos];
-           bitcnt = 0;
-       }
-       else
-           bmp <<= 1;
    }
    self->cursTuple++;
    return TRUE;