Git branches behaving strangely

Question

It seems like I have inadvertently modified my git config such that when I switch from branchA to master all changes are automatically merged to master. This happens without either my committing in branchA or my merging to master. In the past if I tried to switch branches after modifying a tracked file and without committing, I got "the uncommitted changes, can't switch branches" message, but now I'm unable to induce that behavior. Something has changed with my git config, but I have no idea what it might be. Does this sound familiar to anyone?

Any help is greatly appreciated.

Ubuntu 10.10
git 1.7.1
github.com

here's my git config -l:

giggle.main-window-maximized=false
giggle.main-window-geometry=993x731+318+160
giggle.history-view-vpane-position=223
giggle.main-window-view=HistoryView
giggle.file-view-vpane-position=153
core.repositoryformatversion=0
core.filemode=true
core.bare=false
core.logallrefupdates=true
remote.origin.fetch=+refs/heads/*:refs/remotes/origin/*
remote.origin.url=**************************************
branch.master.remote=origin
branch.master.merge=refs/heads/master
submodule.config/shared_capistrano.url=******************capistrano.git
submodule.vendor/plugins/authentication_client.url=********************.git
branch.dev.remote=origin
branch.dev.merge=refs/heads/dev
branch.1.3.9.remote=origin
branch.1.3.9.merge=refs/heads/1.3.9

Answer 1

When you are switching branch and the files are only locally modified, Git will not give you the warning / message ( and will merge the changes into the other branch). For example, you have your repo on master, create a branch temp, have a local modification on the file. Now, when you switch to master you won't get the message. If on the other hand you makes changes in temp and commit them ( that is temp diverges from master ) and then you have local modifications, it will give you that message when you switch to master