fix another segfault

Author: dbsanfte

.gitignore

@@ -32,6 +32,8 @@
 .swiftpm
 .vs/
 .vscode/
+.devcontainer/
+.github/copilot-instructions.md
 nppBackup
 
 
@@ -147,3 +149,4 @@ poetry.toml
 /run-vim.sh
 /run-chat.sh
 Testing/Temporary/CTestCostData.txt
+

src/llama-model-loader.cpp

@@ -874,9 +874,9 @@ void llama_model_loader::init_mappings(bool prefetch, llama_mlocks * mlock_mmaps
 
             // The unified mapping represents all files, so we need to store it
             // for each file index to maintain compatibility with existing code
-            size_t total_size = unified_mapping->size();
             for (size_t i = 0; i < files.size(); ++i) {
-                mmaps_used.emplace_back(total_size, 0);
+                // For mmaps_used, store the individual file size, not the total unified size
+                mmaps_used.emplace_back(files[i]->size(), 0);
                 if (mlock_mmaps && i == 0) { // Only lock once for the unified mapping
                     std::unique_ptr<llama_mlock> mlock_mmap(new llama_mlock());
                     mlock_mmap->init(unified_mapping->addr());
@@ -1254,6 +1254,11 @@ bool llama_model_loader::load_all_data(
                 const auto & mmap_used = mmaps_used.at(idx);
                 auto & mapping = mappings.at(idx);
 
+                // Skip null mappings (can happen with unified NUMA mappings)
+                if (!mapping) {
+                    continue;
+                }
+                
                 // Check if this mapping uses NUMA mirroring
                 // If so, skip the unmap_fragment calls as cleanup is handled in the destructor
                 bool is_numa_mirrored = false;