leafpad fails to compile with compiler flags which elevate common string formatting issues into an error (-Wformat -Wformat-security -Werror=format-security). Jussi is working on replacing leafpad with a different minimal editor, that editor should be tested for string formatting problems and any issues resolved instead of fixing leafpad.
At, http://lists.openembedded.org/pipermail/openembedded-core/2016-May/121479.html
Merge at, http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?h=master-next&id=b830a97f9e8d059ff4ffc345fe216348862a77e9