[PATCH 6/7] dlls/sane.ds: Read frame data until EOF in native transfer mode

[Bernd Herd]

From: Bernd Herd

Makes sure SANE transistions to the next frame on some backends.
---
 dlls/sane.ds/ds_image.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/dlls/sane.ds/ds_image.c b/dlls/sane.ds/ds_image.c
index a1e7d91553b..fa39de85277 100644
--- a/dlls/sane.ds/ds_image.c
+++ b/dlls/sane.ds/ds_image.c
@@ -465,7 +465,11 @@ TW_UINT16 SANE_ImageNativeXferGet (pTW_IDENTITY pOrigin,

twRC = SANE_CALL( read_data, &params );
             if (twRC != TWCC_SUCCESS) break;
-            if (retlen < activeDS.frame_params.bytes_per_line) break;
+            if (retlen < activeDS.frame_params.bytes_per_line)
+            {   /* EOF reached */
+                i = -2;
+                break;
+            }
             /* TWAIN: for 24 bit color DIBs, the pixels are stored in BGR order */
             if (activeDS.frame_params.format == FMT_RGB && activeDS.frame_params.depth == 8)
             {
@@ -489,6 +493,29 @@ TW_UINT16 SANE_ImageNativeXferGet (pTW_IDENTITY pOrigin,
             return TWRC_FAILURE;
         }

+        while (i>=-1)
+          {
+            /* Some backends can deliver more data than requestes, especially
+             * in ADF-Mode.
+             * Dummy-Read until EOF, else the rest of the image might be read
+             * as another (nearly empty) frame. Observed with brscan4 driver */
+            BYTE *line = (BYTE *) malloc(activeDS.frame_params.bytes_per_line);
+            if (line)
+              {
+                int retlen;
+                struct read_data_params params = { line, activeDS.frame_params.bytes_per_line, &retlen };
+                if (SANE_CALL( read_data, &params ) != TWCC_SUCCESS ||
+                    retlen != activeDS.frame_params.bytes_per_line)
+                  {
+                    // EOF reached
+                    i = -2;
+                  }
+                free(line);
+              }
+          }
+
+        activeDS.progressWnd = ScanningDialogBox(activeDS.progressWnd, -1);
+
         GlobalUnlock(hDIB);

*pHandle = (TW_HANDLE)hDIB;