Here's my personnal tip for this one. That solution avoid face and texture loss.

For the following exemple, let's suppose there's 4 segments A,B,C and D, hence 5 end points 1 to 5.
.-.-.-.-.
1A2B3C4D5

1. Make sure the line is split in 3 or more segments.
   1.1 If not, simply use the Line tool to create one more, no matter where.
2. Select all segments but the left and right most ones (segments B and C).
   3.1 Use the Move tool
   3.2 Click the left most selected end point (2) as the move source.
   3.3 Click the right most end point of the whole line (5) as the move target.
3. All the middle segments will be moved outside of the original line. Simply delete the moved segmented. The remaining segment between end points 1 and 5 will be a single unsegmented line.