fix: correct sampling when gamma is 0 (#3093)

Author: mashb1t

ldm_patched/k_diffusion/sampling.py

@@ -832,5 +832,7 @@ def sample_tcd(model, x, sigmas, extra_args=None, callback=None, disable=None, n
         if eta > 0 and sigmas[i + 1] > 0:
             noise = noise_sampler(sigmas[i], sigmas[i + 1])
             x = x / alpha_prod_s[i+1].sqrt() + noise * (sigmas[i+1]**2 + 1 - 1/alpha_prod_s[i+1]).sqrt()
+        else:
+            x *= torch.sqrt(1.0 + sigmas[i + 1] ** 2)
 
     return x