Related to https://fogbugz.unity3d.com/default.asp?543213 (Mac FileMerge says "Unable to compare files" when merging text asset files)

Build from editor/vcsintegration. Changeset: 5a77d4187e309e234aa0ebc5f3ec136a7639ec35 [5a77d4187e30]

Prerequisite: Project with at least one asset (Material in this case). Two clients working on the project through Perforce. Both clients has latest version. Asset Serialization Mode is set to "Force Text"

1. Client #1: Modify material and submit
2. Client #2: Modify same material and submit. Result: Conflicts, so a new changeset is created which must be resolved
3. Client #2: Right-click changeset and choose "Resolve Conflicts..."
4. Client #2: In "Version Control Resolve" window click the "merging" button

Result: Unity says "This is an umergeable file", but when resolving the same changelist from P4V, it is possible using P4Merge visual/text merge tool. See attached screenshot.