User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.3) Gecko/20100423 Ubuntu/10.04 (lucid) Firefox/3.6.3 Build Identifier: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.3) Gecko/20100423 Ubuntu/10.04 (lucid) Firefox/3.6.3 Occasionally, when going back in history, firefox pops up a dialog box: "To display this page, Firefox must send information that will repeat any action (such as a search or order confirmation) that was performed earlier." Why would Firefox need to do such nonsense? Fortunately, this doesn't happen when just switching between tabs. Reproducible: Sometimes Steps to Reproduce: 1.Go back in history Actual Results: Weird dialog "To display this page, Firefox must send information that will repeat any action (such as a search or order confirmation) that was performed earlier." Expected Results: Firefox should just go back without sending anything over the network. It has what it needs in memory, that's why it's called "back". Or is this because limit history memory? Nope, this occurs when just going back to previous page, not something outrageous as 20 pages back.

This is because webpages are sent with a "no-cache" header instructing browsers not to store the page in history.

This seems to be a rather annoying thing that web servers are even allowed to disable history in such a way. Could we get a config setting to make Firefox ignore such user-unfriendly instructions?

I now read in this other bug that this is for preventing next users in a cybercafé to go "back" to back transaction pages of a previous user. But couldn't a user having done online banking in a cybercafé just close the tab or window that he used, so the next user would have no way to go "back" to these pages? Or is there some other way to go back in history, which does not depend on the next page to stay open? In that case, maybe only apply the "no history" hint to that other method? Not to mention that doing online banking in a cybercafé is a dangerous idea even without the possibility to go back in history due to keystroke loggers and other such niceties. Or maybe we could have a config option saying "this is a non-shared computer" so keeping history is always safe.

Mardeg, I think your comment here is wrong. There is no header instructing browsers not to store the page in history, and the "no-cache" is used for something else entirely, as explained by the very detailed comment by Roger Lynn on comment 143 of bug 160144, quoting the relevant RFC's. https://bugzilla.mozilla.org/show_bug.cgi?id=160144#c143