Fix: expressions in random_switch cases should use the parent/self-sc…

…ope of the random_switch.

Regular switches already behaved this way.
For random_switches with BACKWARD/FORWARD-scope there is no sane behavior, but these scopes are pretty useless anyway.

nml/actions/action2random.py

@@ -334,7 +334,14 @@ def parse_randomswitch(random_switch):
     for choice in random_switch.choices:
         res_prob = resulting_prob[choice]
         result, comment = action2var.parse_result(
-            choice.result.value, action_list, act6, offset, random_action2, None, 0x89, res_prob
+            choice.result.value,
+            action_list,
+            act6,
+            offset,
+            random_action2,
+            None,
+            0x8A if type_byte == 0x83 else 0x89,
+            res_prob,
         )
         offset += res_prob * 2
         comment = "({:d}/{:d}) -> ({:d}/{:d}): ".format(choice.probability.value, total_prob, res_prob, nrand) + comment

nml/ast/switch.py

@@ -14,7 +14,7 @@
 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA."""
 
 from nml import expression, generic, global_constants
-from nml.actions import action2, action2random, action2var
+from nml.actions import action2, action2random, action2var, action2var_variables
 from nml.ast import base_statement, general
 
 var_ranges = {"SELF": 0x89, "PARENT": 0x8A}
@@ -319,8 +319,13 @@ def __init__(self, param_list, choices, pos):
         self.random_act2 = None  # Set during action generation to resolve dependent/independent chains
 
     def pre_process(self):
+        feature = next(iter(self.feature_set))
+        # var_feature is really weird for type=BACKWARD/FORWARD.
+        # Expressions in cases will still refer to the origin vehicle.
+        var_feature = action2var_variables.varact2parent_scope[feature] if self.type.value == "PARENT" else feature
+
         for choice in self.choices:
-            choice.reduce_expressions(next(iter(self.feature_set)))
+            choice.reduce_expressions(var_feature)
 
         for dep_list in (self.dependent, self.independent):
             for i, dep in enumerate(dep_list[:]):

regression/035_switch_scope.nml

@@ -0,0 +1,40 @@
+grf {
+    grfid: "NML\35";
+    name: string(STR_REGRESSION_NAME);
+    desc: string(STR_REGRESSION_DESC);
+    version: 0;
+    min_compatible_version: 0;
+}
+
+random_switch(FEAT_INDUSTRYTILES, SELF, random1, bitmask(TRIGGER_INDUSTRYTILE_TILELOOP)) {
+    2: relative_x < 2;
+    1: relative_y > 5;
+}
+
+switch(FEAT_INDUSTRYTILES, SELF, var1, town_zone) {
+    0: relative_x < 2;
+    default: relative_y > 5;
+}
+
+random_switch(FEAT_INDUSTRYTILES, PARENT, random2, bitmask(TRIGGER_INDUSTRYTILE_TILELOOP)) {
+    2: founder_colour1 < 2;
+    1: founder_colour2 > 5;
+}
+
+switch(FEAT_INDUSTRYTILES, PARENT, var2, production_level) {
+    0: founder_colour1 < 2;
+    default: founder_colour2 > 5;
+}
+
+item(FEAT_INDUSTRYTILES, coal_mine) {
+    property {
+        substitute: 0;
+        override: 0;
+    }
+    graphics {
+        foundations: random1;
+        autoslope: random2;
+        anim_speed: var1;
+        anim_control: var2;
+    }
+}

regression/expected/035_switch_scope.nfo

@@ -0,0 +1,144 @@
+// Automatically generated by GRFCODEC. Do not modify!
+// (Info version 32)
+// Escapes: 2+ 2- 2< 2> 2u< 2u> 2/ 2% 2u/ 2u% 2* 2& 2| 2^ 2sto = 2s 2rst = 2r 2psto 2ror = 2rot 2cmp 2ucmp 2<< 2u>> 2>>
+// Escapes: 71 70 7= 7! 7< 7> 7G 7g 7gG 7GG 7gg 7c 7C
+// Escapes: D= = DR D+ = DF D- = DC Du* = DM D* = DnF Du<< = DnC D<< = DO D& D| Du/ D/ Du% D%
+// Format: spritenum imagefile depth xpos ypos xsize ysize xrel yrel zoom flags
+
+0 * 4 \d20
+
+1 * 54 14 "C" "INFO"
+"B" "VRSN" \w4 \dx00000000
+"B" "MINV" \w4 \dx00000000
+"B" "NPAR" \w1 00
+"B" "PALS" \w1 "A"
+"B" "BLTR" \w1 "8"
+00
+00
+2 * 52 08 08 "NML\35" "NML regression test" 00 "A test newgrf testing NML" 00
+// Name: @return_action_0
+3 * 34 02 09 FF 89
+43 20 \dx000000FF
+\2cmp 1A 20 \dx00000002
+\2< 1A 20 \dx00000001
+\2^ 1A 00 \dx00000001
+\b0
+\wx8000 // Return computed value
+
+// Name: @return_action_1
+4 * 34 02 09 FE 89
+43 28 \dx000000FF
+\2cmp 1A 20 \dx00000005
+\2- 1A 20 \dx00000001
+\2> 1A 00 \dx00000000
+\b0
+\wx8000 // Return computed value
+
+// Name: random1
+5 * 15 02 09 FE 80 01 \b0 04
+\wx00FF \wx00FF \wx00FF // (2/3) -> (3/4): return (var[0x43, 0, 255] < 2)
+\wx00FE // (1/3) -> (1/4): return (var[0x43, 8, 255] > 5)
+
+// Name: @return_action_0
+6 * 34 02 09 FF 89
+43 20 \dx000000FF
+\2cmp 1A 20 \dx00000002
+\2< 1A 20 \dx00000001
+\2^ 1A 00 \dx00000001
+\b0
+\wx8000 // Return computed value
+
+// Name: @return_action_1
+7 * 34 02 09 FD 89
+43 28 \dx000000FF
+\2cmp 1A 20 \dx00000005
+\2- 1A 20 \dx00000001
+\2> 1A 00 \dx00000000
+\b0
+\wx8000 // Return computed value
+
+// Name: var1
+8 * 23 02 09 FD 89
+42 00 \dx00000007
+\b1
+\wx00FF \dx00000000 \dx00000000 	// 0 .. 0: return (var[0x43, 0, 255] < 2)
+\wx00FD // default: return (var[0x43, 8, 255] > 5)
+
+// Name: @return_action_2
+9 * 34 02 09 FF 8A
+45 38 \dx0000000F
+\2cmp 1A 20 \dx00000002
+\2< 1A 20 \dx00000001
+\2^ 1A 00 \dx00000001
+\b0
+\wx8000 // Return computed value
+
+// Name: @return_action_3
+10 * 34 02 09 FC 8A
+45 3C \dx0000000F
+\2cmp 1A 20 \dx00000005
+\2- 1A 20 \dx00000001
+\2> 1A 00 \dx00000000
+\b0
+\wx8000 // Return computed value
+
+// Name: random2
+11 * 15 02 09 FC 83 01 \b0 04
+\wx00FF \wx00FF \wx00FF // (2/3) -> (3/4): return (var[0x45, 24, 15] < 2)
+\wx00FC // (1/3) -> (1/4): return (var[0x45, 28, 15] > 5)
+
+// Name: @return_action_0
+12 * 34 02 09 FF 8A
+45 38 \dx0000000F
+\2cmp 1A 20 \dx00000002
+\2< 1A 20 \dx00000001
+\2^ 1A 00 \dx00000001
+\b0
+\wx8000 // Return computed value
+
+// Name: @return_action_1
+13 * 34 02 09 FB 8A
+45 3C \dx0000000F
+\2cmp 1A 20 \dx00000005
+\2- 1A 20 \dx00000001
+\2> 1A 00 \dx00000000
+\b0
+\wx8000 // Return computed value
+
+// Name: var2
+14 * 23 02 09 FB 8A
+93 00 \dx000000FF
+\b1
+\wx00FF \dx00000000 \dx00000000 	// 0 .. 0: return (var[0x45, 24, 15] < 2)
+\wx00FB // default: return (var[0x45, 28, 15] > 5)
+
+15 * 11 00 09 \b2 01 FF \wx0000
+08 00
+09 00
+
+16 * 9 00 09 \b1 01 FF \wx0000
+0E 62
+
+// Name: @CB_FAILED_LAYOUT09
+17 * 17 02 09 FF \b0 \dx00000000
+\dx00000000 \b0 \b0 \b0 \b0 \b0
+// Name: @CB_FAILED09
+18 * 23 02 09 FF 89
+0C 00 \dx0000FFFF
+\b1
+\wx8000 \dx00000000 \dx00000000 	// graphics callback -> return 0
+\wx00FF // Non-graphics callback, return graphics result
+
+// Name: @action3_0
+19 * 53 02 09 FF 89
+0C 00 \dx0000FFFF
+\b4
+\wx00FB \dx00000025 \dx00000025 	// var2;
+\wx00FD \dx00000027 \dx00000027 	// var1;
+\wx00FE \dx00000030 \dx00000030 	// random1;
+\wx00FC \dx0000003C \dx0000003C 	// random2;
+\wx00FF // @CB_FAILED09;
+
+20 * 7 03 09 01 00 \b0
+\wx00FF 	// @action3_0;
+