System Information
Operating system: Windows 10 Home, Ubuntu 18.04
Graphics card: builtin Intel GPU on Windows, Nvidia 1050 Ti on Ubuntu

Blender Version2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: f6cb5f54494e
Works: recent development versions for 2.81

Short description of error

Grid mesh with subdivisions produce incorrect UV maps, depending on the number of subdivisions

Exact steps for others to reproduce the error
See the following script. Doing it manually gives identical results. Didn't find a pattern. Tried developer build from today and yesterday, those work as expected, i.e. produce a UV pattern like in "Correct" for all number pairs that I tried.

import bpy
w=1762
h=896
bpy.ops.mesh.primitive_grid_add(x_subdivisions=w, y_subdivisions=h, size=1.0, enter_editmode=False, location=(0,0,0))
grid=bpy.context.active_object
grid.name="Kaputt2"

w=1763
h=896
bpy.ops.mesh.primitive_grid_add(x_subdivisions=w, y_subdivisions=h, size=1.0, enter_editmode=False, location=(0,0,0))
grid=bpy.context.active_object
grid.name="Correct"