From d635846b8da4809159b1f5f2a591b97bc162df6d Mon Sep 17 00:00:00 2001
From: Roland Tannous <rolandtannous@gravityq.ai>
Date: Tue, 10 Mar 2026 19:13:03 +0000
Subject: [PATCH] fix: use exact variant matching and shard-prefix discovery
 for split GGUFs

Substring matching (e.g. "Q8_0" in filename) could match superset
variants like "IQ8_0", causing wrong quantizations to be downloaded.
Now uses word-boundary regex for variant matching and discovers split
shards by shared filename prefix rather than treating all variant
matches as shards.
---
 studio/backend/core/inference/llama_cpp.py | 28 +++++++++++++++++-----
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/studio/backend/core/inference/llama_cpp.py b/studio/backend/core/inference/llama_cpp.py
index b394284532..934062f56b 100644
--- a/studio/backend/core/inference/llama_cpp.py
+++ b/studio/backend/core/inference/llama_cpp.py
@@ -255,16 +255,32 @@ class LlamaCppBackend:
                 if hf_variant:
                     # Try common naming patterns
                     try:
+                        import re
                         from huggingface_hub import list_repo_files
                         files = list_repo_files(hf_repo, token=hf_token)
                         variant_lower = hf_variant.lower()
-                        matching = sorted(
-                            f for f in files
-                            if f.endswith(".gguf") and variant_lower in f.lower()
+                        # Use word-boundary matching so "Q8_0" doesn't also
+                        # match "IQ8_0" or other superset variant names.
+                        boundary = re.compile(
+                            r'(?<![a-zA-Z0-9])' + re.escape(variant_lower) + r'(?![a-zA-Z0-9])'
                         )
-                        if matching:
-                            gguf_filename = matching[0]  # first shard (or single file)
-                            gguf_extra_shards = matching[1:]  # remaining shards if split
+                        gguf_files = sorted(
+                            f for f in files
+                            if f.endswith(".gguf") and boundary.search(f.lower())
+                        )
+                        if gguf_files:
+                            gguf_filename = gguf_files[0]
+                            # For split GGUFs (e.g. model-Q8_0-00001-of-00003.gguf)
+                            # discover siblings by shared prefix instead of
+                            # trusting all variant matches to be shards.
+                            shard_pat = re.compile(r'^(.*)-\d{5}-of-\d{5}\.gguf$')
+                            m = shard_pat.match(gguf_filename)
+                            if m:
+                                prefix = m.group(1)
+                                gguf_extra_shards = [
+                                    f for f in gguf_files[1:]
+                                    if f.startswith(prefix + "-") and shard_pat.match(f)
+                                ]
                     except Exception as e:
                         logger.warning(f"Could not list repo files: {e}")