fix: Handle "relative" and "proportional" with encumbrance

data/json/items/armor/ballistic_armor.json

@@ -57,7 +57,6 @@
     "price_postapoc": "15 USD",
     "//": "Mono-material as it likely would need to be taken apart to repair, plus the material of the vest is less of a factor on resistances.",
     "material": [ "soil" ],
-    "coverage": 85,
     "encumbrance": 45,
     "material_thickness": 6,
     "extend": { "flags": [ "OVERSIZE", "FRAGILE" ] },

data/json/items/armor/torso_armor.json

@@ -440,7 +440,6 @@
     "description": "A cuirass made from large pieces of carved bone, laced together like lamellar armor.  Tough but stiff, and a bit brittle.",
     "material": [ "bone_heavy" ],
     "color": "white",
-    "encumbrance": 12,
     "warmth": 12,
     "environmental_protection": 1,
     "valid_mods": [  ],

data/mods/TEST_DATA/items.json

@@ -785,5 +785,35 @@
     "name": { "str": "damageable anti-bullet armor" },
     "description": "This armor protects from bullets, but can be damaged to protect a bit less.",
     "material_thickness": 10
+  },
+  {
+    "id": "test_override_armor_copyfrom_encumbrance",
+    "repairs_like": "survivor_suit",
+    "type": "ARMOR",
+    "category": "armor",
+    "name": { "str": "copyable armor with encumbrance" },
+    "description": "This armor has some encumbrance.",
+    "weight": "100 g",
+    "volume": "1 L",
+    "price": 1,
+    "price_postapoc": 1,
+    "symbol": "[",
+    "looks_like": "touring_suit",
+    "color": "dark_gray",
+    "material": [ "cotton" ],
+    "warmth": 0,
+    "material_thickness": 1,
+    "encumbrance": 10,
+    "coverage": 100,
+    "covers": [ "torso", "arm_l", "arm_r", "head", "leg_l", "leg_r" ]
+  },
+  {
+    "id": "test_override_armor_copyfrom_proportional_encumbrance",
+    "copy-from": "test_override_armor_copyfrom_encumbrance",
+    "type": "ARMOR",
+    "category": "armor",
+    "name": { "str": "proportionally encumbering armor" },
+    "description": "This armor has half the encumbrance of some other armor.",
+    "proportional": { "weight": 0.5, "encumbrance": 0.5, "price": 10, "warmth": 2 }
   }
 ]

src/item_factory.cpp

@@ -2035,16 +2035,20 @@ void Item_factory::load( islot_armor &slot, const JsonObject &jo, const std::str
             assign_coverage_from_json( jo, "covers", temp_cover_data, slot.sided );
             slot.data[0].covers = temp_cover_data;
         } else { // This item has copy-from and already has taken data from parent
-            if( jo.has_int( "encumbrance" ) ) {
-                slot.data[0].encumber = jo.get_int( "encumbrance" );
+            if( slot.data.size() > 1 && ( jo.has_int( "encumbrance" ) ||
+                                          jo.has_int( "max_encumbrance" ) ||
+                                          jo.has_int( "coverage" ) ) ) {
+                jo.throw_error( "Legacy armor format only supported for items with exactly 1 armor data entry.  Use \"armor_portion_data\" instead." );
+            }
+            // DISGUSTING hack
+            int old_encumbrance = slot.data[0].encumber;
+            assign( jo, "encumbrance", slot.data[0].encumber, strict );
+            if( old_encumbrance != slot.data[0].encumber ) {
                 slot.data[0].max_encumber = slot.data[0].encumber;
             }
-            if( jo.has_int( "max_encumbrance" ) ) {
-                slot.data[0].max_encumber = jo.get_int( "max_encumbrance" );
-            }
-            if( jo.has_int( "coverage" ) ) {
-                slot.data[0].coverage = jo.get_int( "coverage" );
-            }
+            assign( jo, "max_encumbrance", slot.data[0].max_encumber, strict );
+
+            assign( jo, "coverage", slot.data[0].coverage, strict );
             body_part_set temp_cover_data;
             assign_coverage_from_json( jo, "covers", temp_cover_data, slot.sided );
             if( temp_cover_data.any() ) {