rename sync_vars_t::uidnext => newuid & fix comment

the purpose of this variable is to hold the UIDNEXT value from before
we started pushing new messages, i.e., the minimal uid we can expect
them to have.

src/sync.c

@@ -155,7 +155,7 @@ typedef struct {
 	int trash_total[2], trash_done[2];
 	int maxuid[2]; /* highest UID that was already propagated */
 	int uidval[2]; /* UID validity value */
-	int uidnext[2]; /* next expected UID; TUID lookup makes sense only for lower UIDs */
+	int newuid[2]; /* TUID lookup makes sense only for UIDs >= this */
 	int smaxxuid; /* highest expired UID on slave */
 } sync_vars_t;
 
@@ -725,8 +725,8 @@ box_selected( int sts, void *aux )
 			return;
 		}
 		if (sscanf( buf, "%63s %63s", buf1, buf2 ) != 2 ||
-		    sscanf( buf1, "%d:%d:%d", &svars->uidval[M], &svars->maxuid[M], &svars->uidnext[M] ) < 2 ||
-		    sscanf( buf2, "%d:%d:%d:%d", &svars->uidval[S], &svars->smaxxuid, &svars->maxuid[S], &svars->uidnext[S] ) < 3) {
+		    sscanf( buf1, "%d:%d:%d", &svars->uidval[M], &svars->maxuid[M], &svars->newuid[M] ) < 2 ||
+		    sscanf( buf2, "%d:%d:%d:%d", &svars->uidval[S], &svars->smaxxuid, &svars->maxuid[S], &svars->newuid[S] ) < 3) {
 			error( "Error: invalid sync state header in %s\n", svars->dname );
 			goto jbail;
 		}
@@ -804,9 +804,9 @@ box_selected( int sts, void *aux )
 				else if (buf[0] == ')')
 					svars->maxuid[S] = t1;
 				else if (buf[0] == '{')
-					svars->uidnext[M] = t1;
+					svars->newuid[M] = t1;
 				else if (buf[0] == '}')
-					svars->uidnext[S] = t1;
+					svars->newuid[S] = t1;
 				else if (buf[0] == '|') {
 					svars->uidval[M] = t1;
 					svars->uidval[S] = t2;
@@ -998,7 +998,7 @@ load_box( sync_vars_t *svars, int t, int minwuid, int *mexcs, int nmexcs )
 		maxwuid = 0;
 	info( "Loading %s...\n", str_ms[t] );
 	debug( maxwuid == INT_MAX ? "loading %s [%d,inf]\n" : "loading %s [%d,%d]\n", str_ms[t], minwuid, maxwuid );
-	DRIVER_CALL_RET(load( svars->ctx[t], minwuid, maxwuid, svars->uidnext[t], mexcs, nmexcs, box_loaded, AUX ));
+	DRIVER_CALL_RET(load( svars->ctx[t], minwuid, maxwuid, svars->newuid[t], mexcs, nmexcs, box_loaded, AUX ));
 }
 
 typedef struct {