Make loading fail if it detects a buildid collision

Author: gbaraldi

src/staticdata.c

@@ -4410,7 +4410,11 @@ static jl_value_t *jl_restore_package_image_from_stream(ios_t *f, jl_image_t *im
             JL_SIGATOMIC_END();
 
             // Add roots to methods
-            jl_copy_roots(method_roots_list, jl_worklist_key((jl_array_t*)restored));
+            int failed = jl_copy_roots(method_roots_list, jl_worklist_key((jl_array_t*)restored));
+            if (failed != 0) {
+                jl_printf(JL_STDERR, "Error copying roots to methods from Module: %s\n", pkgname);
+                abort();
+            }
             // Insert method extensions and handle edges
             int new_methods = jl_array_nrows(extext_methods) > 0;
             if (!new_methods) {

src/staticdata_utils.c

@@ -736,17 +736,31 @@ static void jl_activate_methods(jl_array_t *external, jl_array_t *internal, size
     }
 }
 
-static void jl_copy_roots(jl_array_t *method_roots_list, uint64_t key)
+static int jl_copy_roots(jl_array_t *method_roots_list, uint64_t key)
 {
     size_t i, l = jl_array_nrows(method_roots_list);
+    int failed = 0;
     for (i = 0; i < l; i+=2) {
         jl_method_t *m = (jl_method_t*)jl_array_ptr_ref(method_roots_list, i);
         jl_array_t *roots = (jl_array_t*)jl_array_ptr_ref(method_roots_list, i+1);
         if (roots) {
             assert(jl_is_array(roots));
+            if (m->root_blocks) {
+                // check for key collision
+                uint64_t *blocks = jl_array_data(m->root_blocks, uint64_t);
+                size_t nx2 = jl_array_nrows(m->root_blocks);
+                for (size_t i = 0; i < nx2; i+=2) {
+                    if (blocks[i] == key) {
+                        // found duplicate block
+                        failed = -1;
+                    }
+                }
+            }
+
             jl_append_method_roots(m, key, roots);
         }
     }
+    return failed;
 }
 
 static jl_value_t *read_verify_mod_list(ios_t *s, jl_array_t *depmods)