When editing multiline strings syntax highlighting continues until end of file

This seems to occur only when I make changes to a backslash at the beginning or end of a line, or insert a new line in the middle of a string. Sometimes this causes string-style syntax highlighting to end at the edited line without reaching the end of the string and sometimes it highlights the entire rest of the file as if I left out the closing quotation mark.

Other than closing and reopening the file, it can generally be corrected by hitting tab on the first line of the string.

I've noticed this using Emacs 25.3.1 on OS X 10.12.6. I could try to reproduce with Linux at home; I'm not generally writing long SQL queries there to have noticed it otherwise.

No file or test is named. Start by reproducing the multiline-string editing cases in Emacs 25.3.1, especially changing a line-ending backslash or inserting a newline in a SQL query, then trace the syntax-highlighting behavior. Done means edits no longer extend highlighting to the wrong range and reopening the file or pressing Tab is unnecessary.

Written by the indexing model from the issue text.