fix MeleeChemicalInjector exploits (#12305)

Content.Server/Chemistry/Components/MeleeChemicalInjectorComponent.cs

@@ -14,5 +14,12 @@ namespace Content.Server.Chemistry.Components
 
         [DataField("transferEfficiency")]
         private float _transferEfficiency = 1f;
+
+        /// <summary>
+        ///     Solution to inject from.
+        /// </summary>
+        [ViewVariables(VVAccess.ReadWrite)]
+        [DataField("solution")]
+        public string Solution { get; set; } = "default";
     }
 }

Content.Server/Weapons/Melee/MeleeWeaponSystem.cs

@@ -155,7 +155,7 @@ public sealed class MeleeWeaponSystem : SharedMeleeWeaponSystem
 
         // If the user is using a long-range weapon, this probably shouldn't be happening? But I'll interpret melee as a
         // somewhat messy scuffle. See also, heavy attacks.
-        _interaction.DoContactInteraction(user, ev.Target); 
+        _interaction.DoContactInteraction(user, ev.Target);
 
         // For stuff that cares about it being attacked.
         RaiseLocalEvent(ev.Target.Value, new AttackedEvent(component.Owner, user, targetXform.Coordinates));
@@ -555,7 +555,7 @@ public sealed class MeleeWeaponSystem : SharedMeleeWeaponSystem
 
     private void OnChemicalInjectorHit(EntityUid owner, MeleeChemicalInjectorComponent comp, MeleeHitEvent args)
     {
-        if (!_solutions.TryGetInjectableSolution(owner, out var solutionContainer))
+        if (!_solutions.TryGetSolution(owner, comp.Solution, out var solutionContainer))
             return;
 
         var hitBloodstreams = new List<BloodstreamComponent>();

Resources/Prototypes/Entities/Mobs/NPCs/spacetick.yml

@@ -60,19 +60,14 @@
     damage:
       groups:
         Brute: 2
-  - type: MeleeChemicalInjector
   - type: SolutionContainerManager
     solutions:
       melee:
         reagents:
         - ReagentId: Toxin
           Quantity: 5
-  - type: RefillableSolution
+  - type: MeleeChemicalInjector
     solution: melee
-  - type: InjectableSolution
-    solution: melee
-  - type: SolutionTransfer
-    maxTransferAmount: 5
   - type: GhostTakeoverAvailable
     prob: 0.33
     makeSentient: true

Resources/Prototypes/Entities/Mobs/NPCs/xeno.yml

@@ -370,19 +370,14 @@
     damage:
       types:
         Piercing: 5
-  - type: MeleeChemicalInjector
   - type: SolutionContainerManager
     solutions:
       melee:
         reagents:
         - ReagentId: Toxin
           Quantity: 50
-  - type: RefillableSolution
+  - type: MeleeChemicalInjector
     solution: melee
-  - type: InjectableSolution
-    solution: melee
-  - type: SolutionTransfer
-    maxTransferAmount: 3
   - type: Fixtures
     fixtures:
     - shape:

Resources/Prototypes/Entities/Objects/Consumable/Food/produce.yml

@@ -132,10 +132,9 @@
     seedId: nettle
   - type: MeleeChemicalInjector
     transferAmount: 6 #To OD someone you would need 2 nettles and about 6-7 hits, the DOT is likely to crit them if they are running away with almost no health
+    solution: food
   - type: Extractable
     grindableSolutionName: food
-  - type: InjectableSolution
-    solution: food
 
 - type: entity
   name: banana

Resources/Prototypes/Entities/Objects/Weapons/Melee/spear.yml

@@ -32,11 +32,12 @@
     graph: Spear
     node: spear
   - type: ItemCooldown
-  - type: MeleeChemicalInjector
   - type: SolutionContainerManager
     solutions:
       melee:
         maxVol: 5
+  - type: MeleeChemicalInjector
+    solution: melee
   - type: RefillableSolution
     solution: melee
   - type: InjectableSolution