As seen on Fabulously Optimized!
This resource pack makes the following blocks use the top texture on their sides as well:
Dirt paths have a special feature - they "spread" to the block below in order to look more seamless on villages.
In other words, the pack imitates OptiFine's Better Grass feature (fast mode) in resource pack form. The imitation is done by solely adjusting vanilla block models, no assets from other mods are used.
FAQ: