Solution : https://service.sap.com/sap/support/notes/913116 (SAP Service marketplace login required)
Key words :
cmd=reset_item&item=gr2chart&width=600&height=400&hidden=& item_id=0query_template_3dcolumns&generate_caption=, cmd%3dreset_item&item%3dgr2chart&width%3d60, expected special character data, simple command urls, exact http call, form field values, american ascii code, returned utf-8 data, web report display, l_string = cl_http_utility=>unescape_url
Related Notes :
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| 886580 | UTF8 Encoded data are passed to the ICM from f4 dialog |
| 850995 | RA variants: Title w/ '+' chars not transferred correctly |
| 840413 | |
| 825036 | Corrupt characters in HTTP form fields |
| 500360 | UTF-8 Escaping in CL_HTTP_UTILITY~ESCAPE_URL/~UNESCAPE_URL |