For the case where a letter is added to the middle of a misspelled word, we were sending incorrect offsets to clear spelling markers. However, since this expanded the current word, it overlaps entirely the previous spelling marker so no issue is found. However, if the keypress is backspace, the incorrect range is smaller, causing an overlap which recreates the marker over the last character. Setting shouldEraseMarkersAfterChangeSelection to follow continuous spell checking, which will clear all markers regardless of overlap. This patch also sustains spelling markers after the user taps to move the caret onto the word, which is a nice gain as it was asked for previously.
Created attachment 205609 [details] Patch
Comment on attachment 205609 [details] Patch Looks good.
Comment on attachment 205609 [details] Patch Clearing flags on attachment: 205609 Committed r152102: <http://trac.webkit.org/changeset/152102>
All reviewed patches have been landed. Closing bug.