erp5_document_scanner: browser may fail to initialize the webgl context

bt5/erp5_document_scanner/PathTemplateItem/web_page_module/scanner_gadget_document_scanner_js.js

@@ -4,7 +4,7 @@
          FileReader, DataView, URL, fx, loadImage */
 (function (rJS, RSVP, window, document, navigator, Cropper, Promise, JSON, jIO,
            promiseEventListener, domsugar, createImageBitmap, FormData, caman,
-           FileReader, DataView, URL, fx) {
+           FileReader, DataView, URL, fx, loadImage) {
   "use strict";
 
   var CROPPER_DATA_JIO_KEY = 'cropperjs_data_',
@@ -568,10 +568,13 @@
             canvas = document.createElement('canvas');
             webgl_context = canvas.getContext('webgl');
 
-            expected_width = Math.min(
-              expected_width || webgl_context.getParameter(webgl_context.MAX_TEXTURE_SIZE),
-              webgl_context.getParameter(webgl_context.MAX_TEXTURE_SIZE) - 1
-            );
+            if (webgl_context !== null) {
+              // Browser fails sometimes to initialize the webgl context
+              expected_width = Math.min(
+                expected_width || webgl_context.getParameter(webgl_context.MAX_TEXTURE_SIZE),
+                webgl_context.getParameter(webgl_context.MAX_TEXTURE_SIZE) - 1
+              );
+            }
 
             if ((!!expected_width) && (expected_width < higher_dimension_value)) {
               load_image_options[higher_dimension_key] = expected_width;
@@ -1116,4 +1119,4 @@
 
 }(rJS, RSVP, window, document, navigator, Cropper, Promise, JSON, jIO,
   promiseEventListener, domsugar, createImageBitmap, FormData, Caman,
-  FileReader, DataView, URL, fx));
\ No newline at end of file
+  FileReader, DataView, URL, fx, loadImage));
\ No newline at end of file

bt5/erp5_document_scanner/PathTemplateItem/web_page_module/scanner_gadget_document_scanner_js.xml

@@ -244,7 +244,7 @@
                   </item>
                   <item>
                       <key> <string>serial</string> </key>
-                      <value> <string>986.32279.2119.1979</string> </value>
+                      <value> <string>994.64153.48955.40226</string> </value>
                   </item>
                   <item>
                       <key> <string>state</string> </key>
@@ -262,7 +262,7 @@
                           </tuple>
                           <state>
                             <tuple>
-                              <float>1599642009.31</float>
+                              <float>1632406703.55</float>
                               <string>UTC</string>
                             </tuple>
                           </state>