The phrase "Ich hätte gerne ein Glas Wasser." is nothing remarkable.
"Ich hätte gerne" can be used to politely ask for something.
But how about this, which I recently heard on German talk radio:
"Ich hätte gerne mal eine Frage: Wie alt ist die Erde?"
This seems to be a Verballhornung (corruption) of "Ich hätte da mal eine Frage" and "Ich hätte gerne ein xxx."
I'm not sure if that was comedy and meant to be funny, or if it was meant as phrased.
Has anyone come across this?
"Ich hätte gerne mal eine Frage" is basically incorrect. Sometimes it's used by comedians, like Robert Treutel does with his Bodo Bach character. Bodo Bach started out by making prank calls in Treutel's radio show with the trademark opening "Isch hätt da gern emal e Problem". This is Hessian dialect (or rather, Hessian-colored High German, to make it digestible for everybody) for "Ich hätte da gerne einmal ein Problem", "I would like to have a problem".
"Ich hätte gerne mal eine Frage" is similar to that, so maybe a comedian on the radio station WDR 5 used it in a similar manner.
It's also possible that it's just a mistake. Maybe you've listened to a call-in show, where people could call to ask a doctor, a lawyer or some other expert. The caller might have been nervous (I'm on the air???) and wanted to be extra polite, getting it all wrong ;)
For example, the newspaper Berliner Morgenpost wrote about a show with Bastian Sick
Auch ein Morgenpost-Leser liefert versehentlich eine Steilvorlage: "Ich hätte da gerne mal eine Frage", sagt er aufgeregt. Sick muss nicht reagieren und etwa klären, ob der Gast eine große oder kleine Frage haben wolle und was er dafür denn ausgeben wolle. Seine Mimik reicht, um beim fachkundigen Publikum dröhnendes Gelächter auszulösen. Und der Fragesteller lacht dann einfach mit.
If you search for the phrase in the search engine of your preference, you'll probably see posts like that on web forums and the like, where people stumbled over themselves trying to be polite.
At the moment this is pure word humor. In the eventuality that the line becomes so popular that more and more people use it, often without quite getting the joke, it might become a normal expression over time.
Ich hätte gerne mal eine Frage.
is a mix of
Ich hätte mal eine Frage.
and
Ich würde gern eine Frage stellen.
It seems to happen, when people are very nervous and very insecure at the same time and therefor trying to be overly polite.
So if it isn't comedy, it's unfreiwillig komisch (unwillingly comical).
Relativisation and limiting the scope by introducing a temporal, spatial, logical or value-based limitation can generally be interpreted as an attempt to "soften" a demand, and thus to make a question more polite. This is because it leaves a bigger space for the asked person to react. This is an explanation of the fact that the use of Konjunktiv (subjunctive) is considered more polite than the use of plain Indikativ. Adding the qualifier gern is an additional limitation of the demand, also raising associations which stem from ordering something. The following sentences are an ordered list of demanding the same, ordered by their degree of politeness:
Ich habe eine Frage.
Ich hätte eine Frage. [Using Konjunktiv as means of relativisation]
Ich hätte mal eine Frage. [Adding "mal" as temporal limitation]
Ich hätte gerne mal eine Frage. [Adding. "gerne" as a value-based limitation]
Ich hätte vielleicht gerne mal eine Frage. [Adding "vielleicht" as logical limitation]
Ich hätte da vielleicht gerne mal eine Frage. [Adding "da" as spatial limitation]
Ich hätte da unter Umständen vielleicht gerne mal eine Frage. [Adding "unter Umständen" as further logical limitation]
This level of politeness can be seen as an exaggeration, and hence it could be meant or taken as ironic. But I would not say, that the phrase is ironic per se.
One could argue that adding gerne changes the "illocutionary force" of the question, i.e. it tells a different intention of the speaker, because by uttering
Ich hätte eine Frage.
the speaker is expressing to have a question, while by
Ich hätte gern eine Frage.
the speaker is expressing the wish to have a question, if you take it literally (I wish I only had a question). Logically this is correct, but since uttering the wish to have a question is clearly not meant, if the question is following directly after, I would say that the cooperative principle directs to the inference, that actually I wish I would get an answer is the intention of the speaker to utter this sentence.
Making the sentence more and more complex, though, will increase the risk of not being taken serious anymore. Speaking in a very stilted manner can also be a means of ironic speech or create a comic impression. Whether one would interpret the sentence given in the question as intentionally or unintentionally comic or ironic, depends on situation and context.
