# Reproduce output in picture using a logical input list by introducing a bug

I came across this picture and thought that this would be a fun programming puzzle to work out. (https://www.reddit.com/r/funny/comments/4hjf4y/ill_take_february_tickets_please)

(Clearly, the drop-down should simply have numbers from 0 to 10, but instead has some numbers replaced by the corresponding word, while others have been replaced by the name of the corresponding month.)

Can you figure out what bug or oversight in well-intentioned code could reproduce this exact output?

The solution has to make sense (like there ought be a correct month list, number list, etc), but should contain a weird 'bug' that messes up the enumerated results to produce this output.

The solution should show the start state, and explain the steps leading to this final state (a retro-grade puzzle).

do note that it is not as simple as odd = month, even = numbers (the "August" and "September" will fail this check).

good luck and have fun with this thought exercise!

• I'm voting to close this question as off-topic because it is not a puzzle or related to puzzling.
– Deusovi
May 3 '16 at 2:10
• @Deusovi I think this could count as a retrograde analysis type puzzle, like this one. May 3 '16 at 2:40
• Just wanted to share the piece of gold you can find by reading through the post linked to... Stupid phone number entry methods May 3 '16 at 17:49
• I think this is a valid retrograde analysis puzzle. The requirement that the intended code should make sense does not make it too broad at all - Can't think of a single reasonable solution, in fact. It doesn't seem to be something simple like only even months because of the September. Longer string doesn't work consistently either. May 3 '16 at 19:46
• This question MAY be more appropriate over at Programming Puzzles and Code Golf (Disclaimer: I am not an active member of that SE, but I have seen questions of a similar vein over there) May 5 '16 at 15:25

I know we aren't necessarily looking for the actual cause of this behavior, but here are a few observations that may help in understanding it.

First, the (alleged) original discoverer of the bug stated that he/she encountered it on Fandango. Though his/her original post is about a year old, the layout of the site doesn't seem to have changed. If so, the relevant piece of code is:

<td class="numberofTickets">
<select name="AreaRepeater$ctl00$TicketRepeater$ctl00$quantityddl"
id="AreaRepeater_TicketRepeater_0_quantityddl_0" tabindex="1"
class="qtyDropDown" name="quantityddl" onchange="javascript:

<option value="0">0</option>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
<option value="8">8</option>
<option value="9">9</option>
<option value="10">10</option>

</select>
</td>


There is nothing here that could possibly produce the output in question, and I found no code that modifies how these drop-downs are displayed.

Second, zeisss also stated that he/she was using Chrome and was unable to reproduce the bug with Firefox. Since I couldn't reproduce it with Chromium, I'm starting to get the impression that the real culprit was an extension.

And someone, I think, has already found out which one.

• I mean, what other extension could there be that is shipped with Chrome, not shipped with other browsers, and could cause this? May 9 '16 at 22:51
• Interesting. But does anyone have a theory on why that extension behaves like this? May 10 '16 at 19:32