GUI-style mouse position handling in text selection

[GoogleCodeExporter]

Mintty takes a "you touched it you selected it" approach to character selection 
with the mouse, i.e. a character cell is included in the selection as soon as 
the mouse touches one of its edges. The Windows console, PuTTY, rxvt, and xterm 
all take the same approach.

However, GUI programs in Windows as well as KDE and GNOME do things 
differently: a character is included in the selection if its centre is between 
the two selection end points. Put another way, for selection purposes the mouse 
isn't considered to be on a character, but between them. This chimes with the 
I-beam shape of the text selection mouse pointer.

KDE Konsole and GNOME Terminal also take that GUI-style approach, so it would 
make plenty of sense for mintty to do the same. It would also alleviate the 
Windows 7 problem reported in issue 305.

Original issue reported on code.google.com by andy.koppe on 19 Dec 2011 at 6:20

[GoogleCodeExporter]

This change should not apply to application mouse mode, because applications 
assume the xterm behaviour of being told which character cell the mouse is on. 
Also, application mouse mode uses the arrow mouse pointer, so it isn't affect 
by issue 305, and the argument about the I-beam shape doesn't apply.

Original comment by andy.koppe on 19 Dec 2011 at 6:24

[GoogleCodeExporter]

Original comment by andy.koppe on 10 Apr 2012 at 12:08

• Changed title: GUI-style mouse position handling in text selection