When inspect.getframeinfo() tries to collect lines of context it never shows the first line (unless context is as big as the number of lines in the file).

The relevant code is

        start = lineno - 1 - context//2
        try:
            lines, lnum = findsource(frame)
        except IOError:
            lines = index = None
        else:
-->         start = max(start, 1)
            start = max(0, min(start, len(lines) - context))
            lines = lines[start:start+context]
            index = lineno - 1 - start

I think that

            start = max(start, 1)

should be replaced by

            start = max(start, 0)

For some reason getframeinfo() (and the functions which use it) don't seem to be tested by the testsuite...