Would be possible, but what if the user starts to type a long search term, and then remembers that a search for this is already there and clicks on the tab to get the text without typing?
he cleans what he's written, and switch the tab, so the entry is overwritten.
Anyway I really don't see the point of starting again a search that has already been completed. Can you better explain?
When you start aMule and immediately start a search, you are most likely connected to just a few nodes, which for sure give you less results. If you start the same search after some time again, you'll get in most cases more results with exactly the same searchterm.
Maybe you should just finish one thing (writing and starting search) before you do something else. You consult your results while you're waiting for the new search to finish.
It might happen (actually it happens lots of time in my case) that while you are writing, you must consult the other results to affine the search query.
Sure, that's the case when you get too much results. This feature is only usefull if you get no or not enough or no good results. But if you want to reduce the search results for term "A", it's not usefull to switch on the tab of "B" which doesn't contain the saerchterm you want to adjust. In most cases you go to tab of "A C" or "A D" maybe to combine them to "A C D", so in this case the feature is still usefull. Or maybe you want to adjust your search to "A B", in this case you have to type either "A" or "B" (or just copy them, for what you still need it to be in the text field). In this case I would like to switch to the tab that contains the longer part and just retype the shorter one.
In any case (given that you use an OS that supports it), you can just mark your term, examine as many tabs as you wish, then click "Clean Fields" (or just keep the tab you want to expand) and then middle-click to get the marked text in there.
Otherwise, if the text wouldn't be taken, you have either to retype the whole term (like for a new, not related search), or if there would be a button to copy the text, you would have to go to the tab, copy the text to the field, makr or copy the text, go to the next tab, copy it again, just to insert the old one.
So you see, current way and your proposed way have the exact opposite targets. And as current way doesn't mean more work than your proposed way in case of the not targetted task than the other around, current way is better as default.