Softwrapping can prevent access to entire line

[GeigerCounter]

Description of the problem or steps to reproduce

1: Open a file with softwrapping turned off.
2: Type a line the goes past the rightmost column or simply scroll into a line that does.
3: Turn on softwrapping.
4: Be unable to scroll back to the start of the line. ( Tried with mouse, arrow keys, and home button )

It seems as though softwrapping treats the left most column on screen as the beginning of a line, so that parts of a line will become inaccessible until you turn off softwrapping, move to the beginning of the line, and toggle softwrapping again. While easy to work around and low priority, this is still a bug.

Specifications

Version: 1.1.5-dev.173
Commit hash: bd5e770
Compiled on April 25, 2017

[dmaluka]

This issue is present again in the current version (apparently the fix was lost after the refactoring). @zyedidia could you reopen it?

It seems the best way to fix it is to update StartCol when changing softwrap option value in SetOptionNative. But it is complicated by the fact that SetOptionNative has no access to the display module.