epsonds: enable double feed detection

backend/epsonds-cmd.c

@@ -607,11 +607,13 @@ static SANE_Status capa_cb(void *userdata, char *token, int len)
 
 		if (strncmp("ADFDFL1", token, 3 + 4) == 0) {
 			DBG(1, "     ADF: double feed detection\n");
+			s->hw->adf_has_dfd = 1;
 		}
 	}
 
 	if (len == 8 && strncmp("ADFDFL1DFL2", token, 3 + 4) == 0) {
 		DBG(1, "     ADF: double feed detection (high sensitivity)\n");
+		s->hw->adf_has_dfd = 2;
 	}
 
 	if (strncmp("FMT", token, 3) == 0) {

backend/epsonds.c

@@ -1189,6 +1189,12 @@ sane_start(SANE_Handle handle)
 			s->val[OPT_ADF_MODE].w ? "DPLX" : "",
 			s->val[OPT_ADF_SKEW].w ? "SKEW" : "");
 
+		if (s->hw->adf_has_dfd == 2) {
+			strcat(buf, "DFL2");
+		} else if (s->hw->adf_has_dfd == 1) {
+			strcat(buf, "DFL1");
+		}
+
 	} else if (strcmp(source_list[s->val[OPT_SOURCE].w], FBF_STR) == 0) {
 
 		strcpy(buf, "#FB ");

backend/epsonds.h

@@ -138,6 +138,7 @@ struct epsonds_device
 	SANE_Bool adf_has_load;		/* supports load command */
 	SANE_Bool adf_has_eject;	/* supports eject command */
 	SANE_Byte adf_alignment;	/* left, center, right */
+	SANE_Byte adf_has_dfd;		/* supports double feed detection */
 
 	SANE_Bool has_tpu;		/* tpu */
 	SANE_Range tpu_x_range;	        /* transparency unit x range */