":set urloperator=" will turn off splitting

used to go into infinite loop

vimperator/locale/en-US/options.txt

@@ -759,7 +759,8 @@ Set the separator regex used to separate multiple URL args. Multiple arguments
 can be specified for [c]:open[c], and similar commands, using this regex as
 the separator. Using whitespace alone is not generally useful since it is often
 contained in a single argument. E.g. [c]:open linus torvalds[c] should perform
-a single search for the key words "linus" and "torvalds"
+a single search for the key words "linus" and "torvalds". If this is set to the
+empty string then these arguments will never be split.
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