1516170 - Mail body: a part of the text is truncated

Status: VERIFIED INVALID

(Thunderbird :: Message Reader UI, defect)

Description

[Jens]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:64.0) Gecko/20100101 Firefox/64.0

Steps to reproduce:

I received email from Thailand (gmail) 'text/plain, charset=utf-8, base64 encoded' and additional in 'text/html, charset=utf-8, base64 encoded'. (followed data is truncated by me for privacy)
Result: "I wish you good luck Have a safe trip...i go to " + mobile signature + quote.
Plain: SSB3aXNoIHlvdSBnb29kIGx1Y2sgSGF2ZSBhIHNhZmUgdHJpcC4uLmkgZ28gdG8gc2xlZXAgbm93
HTML: PGh0bWw+PGhlYWQ+PG1ldGEgaHR0cC1lcXVpdj0iQ29udGVudC1UeXBlIiBjb250ZW50PSJ0ZXh0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Actual results:

The written text is truncated, while the quote of the old mail is properly shown at bottom (any view). A forward of this mail to thunderbird account leads to the same result. A forward of this mail to android account makes the 'hidden' text visible.  


Expected results:

The complete text should be shown, like the android mail app and the browser does.

Comment 1

[Jorg K (CEST = GMT+2)]

We need to full e-mail to see what's going on. You can forward it to me as attachment and I won't disclose it ;-)

Comment 2

[Jorg K (CEST = GMT+2)]

I received the message in question in a private e-mail from the reporter.

It is a typical multipart/alternative message with a plaintext and HTML part.

Displaying the HTML part, we see:
I wish you good luck Have a safe trip...i go 
and some more stuff. It looks truncated after the "i go".

However, do this:
Paste the full HTML part starting with PGh0bWw+PGhlYWQ+ into https://www.base64decode.org/.

Then paste the obtained HTML and store it into a file, open the file with Firefox.

Although the HTML contains:
I wish you good luck Have a safe trip...i go to sleep now (and more)
we only see upto the "i go".

Why, because there is CSS in the message that says:
<pre class="tw-data-text tw-ta tw-text-small" data-placeholder="คำแปล" id="tw-target-text" data-fulltext="" dir="ltr" style="max-height: 999999px; background-color: rgb(255, 255, 255); border: none; padding: 0px 0.14em 0px 0px; position: relative; margin-top: 0px; margin-bottom: 0px; resize: none; font-family: inherit; overflow: hidden; width: 312px; white-space: pre-wrap; overflow-wrap: break-word; color: rgb(33, 33, 33); height: 20px; font-size: 16px !important;">

So the first section will be rendered at 312px, and the CSS says that any overflow is *hidden*, so whatever is cut off is invisible.

Conclusion: INVALID.

To see the it better, do: View > Message Body As > Simple HTML or Plain Text. Simple HTML ignores the CSS and you see everything.

Note: Firefox has a world-class rendering engine that renders HTML absolutely correctly. Thunderbird uses the same Mozilla technology. So if it doesn't show correctly, it's the fault of the HTML.

The reporter mentioned that Outlook displays the same which would be the correct thing to so. Of course, if you forward the message to another device using other software which doesn't honour the HTML, then you might get different results showing the otherwise hidden text.