Affects Version/s: Minecraft 15w38b, Minecraft 15w39b, Minecraft 15w40a
Fix Version/s: Minecraft 15w49a
When summoning an AreaEffectCloud, the following particles do not display:
Further explanation by [Mod] Skylinerw:
What's happening is that the possible particle IDs (found in class 'cy') are checked exactly. "blockcrack_", "iconcrack_", and "blockdust_" are the exact IDs, meaning "blockcrack_1" is seen as an invalid ID since it doesn't match; it's not interpreting what the "1" means up to this point, thus the correct format for those types of particles is essentially irrelevant.
From the AreaEffectCloud entity class (ra.java), where it attempts to read NBT data (accessed via /summon):
In summary: for each particle ID there is, check if the input from the "Particle" tag matches it exactly. If so, that will be the particle used. A small section from the list in ParticleTypes (cy.java):
If the input was "barrier", then it matches perfectly. However, if the input is "blockcrack_1", then it doesn't since there's no corresponding particle ID. If the input is "blockcrack_", then it matches the ID from the list and is the chosen particle. The game will crash when doing so though, as mrpingouin1 pointed out.
So the problem comes from the AreaEffectCloud class matching particle IDs with the "Particle" tag, since the particle ID is checked as literally typed (it can't determine that "blockcrack_1" is the intended "blockcrack_" ID).
The /particle command differs from this because it checks on its own if the intended ID is one of the underscored IDs, which is why it can work there (as well as preventing the use of just "blockcrack_").