Fix things

What's the point of having a definition for infinite charges if it's not used?

Reorganizes ammo_count_for function

src/character_functions.cpp

@@ -1179,43 +1179,38 @@ std::vector<item_location> find_reloadables( const Character &who )
 
 int ammo_count_for( const Character &who, const item &gun )
 {
-    int ret = item::INFINITE_CHARGES;
     if( !gun.is_gun() ) {
-        return ret;
+        return item::INFINITE_CHARGES;
     }
+    int ammo_drain = gun.ammo_required();
+    int energy_drain = gun.get_gun_ups_drain();
 
-    int required = gun.ammo_required();
+    units::energy power = units::from_kilojoule( who.charges_of( itype_UPS ) );
+    int total_ammo = gun.ammo_remaining();
+    const std::vector<item_location> inv_ammo = find_ammo_items_or_mags( who, gun, true, -1 );
 
-    if( required > 0 ) {
-        int total_ammo = 0;
-        total_ammo += gun.ammo_remaining();
+    bool has_mag = gun.magazine_integral();
 
-        bool has_mag = gun.magazine_integral();
-
-        const auto found_ammo = find_ammo_items_or_mags( who, gun, true, -1 );
-        int loose_ammo = 0;
-        for( const auto &ammo : found_ammo ) {
-            if( ammo->is_magazine() ) {
-                has_mag = true;
-                total_ammo += ammo->ammo_remaining();
-            } else if( ammo->is_ammo() ) {
-                loose_ammo += ammo->charges;
-            }
-        }
-
-        if( has_mag ) {
-            total_ammo += loose_ammo;
+    for( const item_location &it : inv_ammo ) {
+        if( it->is_magazine() ) {
+            total_ammo += it->ammo_remaining();
+        } else if( it->is_ammo() && has_mag ) {
+            total_ammo += it->count();
         }
-
-        ret = std::min( ret, total_ammo / required );
     }
 
-    int ups_drain = gun.get_gun_ups_drain();
-    if( ups_drain > 0 ) {
-        ret = std::min( ret, who.charges_of( itype_UPS ) / ups_drain );
+    if( ammo_drain > 0 && energy_drain > 0 ) {
+        // Both UPS and ammo, lower is limiting.
+        return std::min( total_ammo, power / units::from_kilojoule( energy_drain ) );
+    } else if( energy_drain > 0 ) {
+        //Only one of the two, it is limiting.
+        return power / units::from_kilojoule( energy_drain );
+    } else if( ammo_drain > 0 ) {
+        return total_ammo;
+    } else {
+        // Effectively infinite ammo.
+        return item::INFINITE_CHARGES;
     }
-
-    return ret;
 }
 
 void show_skill_capped_notice( const Character &who, const skill_id &id )

src/item_functions.cpp

@@ -56,7 +56,7 @@ int shots_remaining( const Character &who, const item &it )
         return it.ammo_remaining();
     } else {
         // Effectively infinite ammo.
-        return 10;
+        return item::INFINITE_CHARGES;
     }
 }
 

src/npc.h

@@ -1391,9 +1391,9 @@ npc *pick_follower();
 namespace npc_ai
 {
 /** Evaluate item as weapon (melee or gun) */
-double weapon_value( const Character &who, const item &weap, int ammo = 10 );
+double weapon_value( const Character &who, const item &weap, int ammo = item::INFINITE_CHARGES );
 /** Evaluates item as a gun */
-double gun_value( const Character &who, const item &weap, int ammo = 10 );
+double gun_value( const Character &who, const item &weap, int ammo = item::INFINITE_CHARGES );
 /** Evaluate item as a melee weapon */
 double melee_value( const Character &who, const item &weap );
 /** Evaluate unarmed melee value */