Fixes to BlockMask and "char" masks (#1787)

* If a char mask  is successfully created from the full input, return it

* Don't double-up adding a block to a BlockMaskBuilder (if adding by regex is successful)
 - InputParseException is thrown if unsuccessful

* Fix optimisation of BlockMask for negation of a single block type
 - Fixes #1755

* Allow early returning of an optimized MaskIntersection to avoid unnecessary work

* Actually allow underscore in isAlphanumericUnd
 - Fixes #1626

* Replace a few more hard-coded air internal IDs

* Don't fail silently if BlockMaskBuilder#addRegex doesn't work when testing all block types

* Remove unused import

worldedit-core/src/main/java/com/fastasyncworldedit/core/extension/factory/parser/mask/RichMaskParser.java

@@ -127,6 +127,9 @@ public class RichMaskParser extends FaweParser<Mask> {
                             case '%', '$', '<', '>', '!' -> {
                                 input = input.substring(input.indexOf(char0) + 1);
                                 mask = parseFromInput(char0 + "[" + input + "]", context);
+                                if (mask != null) {
+                                    return mask;
+                                }
                             }
                             case '#' -> {
                                 if (!(input.charAt(1) == '#')) {
@@ -145,6 +148,10 @@ public class RichMaskParser extends FaweParser<Mask> {
                             try {
                                 builder.addRegex(full);
                             } catch (InputParseException ignored) {
+                                context.setPreferringWildcard(false);
+                                context.setRestricted(false);
+                                BaseBlock block = worldEdit.getBlockFactory().parseFromInput(full, context);
+                                builder.add(block);
                             } catch (PatternSyntaxException e) {
                                 throw new SuggestInputParseException(
                                         new NoMatchException(Caption.of("fawe.error.parse.unknown-mask", full,
@@ -166,10 +173,6 @@ public class RichMaskParser extends FaweParser<Mask> {
                                         }
                                 );
                             }
-                            context.setPreferringWildcard(false);
-                            context.setRestricted(false);
-                            BaseBlock block = worldEdit.getBlockFactory().parseFromInput(full, context);
-                            builder.add(block);
                             mask = builder.build(extent);
                         }
                     }

worldedit-core/src/main/java/com/fastasyncworldedit/core/function/mask/BlockMaskBuilder.java

@@ -123,7 +123,7 @@ public class BlockMaskBuilder {
             if (input.charAt(input.length() - 1) == ']') {
                 int propStart = StringMan.findMatchingBracket(input, input.length() - 1);
                 if (propStart == -1) {
-                    return;
+                    throw new InputParseException(Caption.of("fawe.error.no-block-found", TextComponent.of(input)));
                 }
 
                 MutableCharSequence charSequence = MutableCharSequence.getTemporal();
@@ -250,11 +250,16 @@ public class BlockMaskBuilder {
                 if (StringMan.isAlphanumericUnd(input)) {
                     add(BlockTypes.parse(input));
                 } else {
+                    boolean success = false;
                     for (BlockType myType : BlockTypesCache.values) {
                         if (myType.getId().matches(input)) {
                             add(myType);
+                            success = true;
                         }
                     }
+                    if (!success) {
+                        throw new InputParseException(Caption.of("fawe.error.no-block-found", TextComponent.of(input)));
+                    }
                 }
             }
         });

worldedit-core/src/main/java/com/fastasyncworldedit/core/util/StringMan.java

@@ -295,7 +295,7 @@ public class StringMan {
     public static boolean isAlphanumericUnd(CharSequence str) {
         for (int i = 0; i < str.length(); i++) {
             final char c = str.charAt(i);
-            if (c < 0x30 || c >= 0x3a && c <= 0x40 || c > 0x5a && c <= 0x60 || c > 0x7a) {
+            if (c < 0x30 || c >= 0x3a && c <= 0x40 || c > 0x5a && c <= 0x60 && c != 0x5f || c > 0x7a) {
                 return false;
             }
         }

worldedit-core/src/main/java/com/sk89q/worldedit/function/mask/BlockMask.java

@@ -210,15 +210,14 @@ public class BlockMask extends ABlockMask {
 
     @Override
     public boolean replacesAir() {
-        return ordinals[1]
+        return ordinals[BlockTypesCache.ReservedIDs.AIR]
-                || ordinals[2]
+                || ordinals[BlockTypesCache.ReservedIDs.CAVE_AIR]
-                || ordinals[3];
+                || ordinals[BlockTypesCache.ReservedIDs.VOID_AIR];
     }
 
     @Override
     public Mask tryCombine(Mask mask) {
-        if (mask instanceof ABlockMask) {
+        if (mask instanceof ABlockMask other) {
-            ABlockMask other = (ABlockMask) mask;
             boolean modified = false;
             boolean hasAny = false;
             for (int i = 0; i < ordinals.length; i++) {
@@ -241,8 +240,7 @@ public class BlockMask extends ABlockMask {
 
     @Override
     public Mask tryOr(Mask mask) {
-        if (mask instanceof ABlockMask) {
+        if (mask instanceof ABlockMask other) {
-            ABlockMask other = (ABlockMask) mask;
             boolean modified = false;
             for (int i = 0; i < ordinals.length; i++) {
                 if (!ordinals[i]) {
@@ -273,23 +271,27 @@ public class BlockMask extends ABlockMask {
 
         int setTypes = 0;
         BlockType setType = null;
+        BlockType unsetType = null;
         int totalTypes = 0;
 
         for (BlockType type : BlockTypesCache.values) {
             if (type != null) {
                 totalTypes++;
                 boolean hasAll = true;
+                boolean hasAny = false;
                 List<BlockState> all = type.getAllStates();
                 for (BlockState state : all) {
                     totalStates++;
-                    hasAll &= test(state);
+                    boolean result = test(state);
+                    hasAll &= result;
+                    hasAny |= result;
                 }
                 if (hasAll) {
                     setTypes++;
                     setType = type;
                     setStates += all.size();
                     setState = type.getDefaultState();
-                } else {
+                } else if (hasAny) {
                     for (BlockState state : all) {
                         if (test(state)) {
                             setStates++;
@@ -298,6 +300,10 @@ public class BlockMask extends ABlockMask {
                             unsetState = state;
                         }
                     }
+                } else if (all.size() == 1) {
+                    unsetState = all.get(0);
+                } else {
+                    unsetType = type;
                 }
             }
         }
@@ -313,7 +319,11 @@ public class BlockMask extends ABlockMask {
         }
 
         if (setStates == totalStates - 1) {
-            return new InverseSingleBlockStateMask(getExtent(), unsetState);
+            if (unsetState != null) {
+                return new InverseSingleBlockStateMask(getExtent(), unsetState);
+            } else {
+                throw new IllegalArgumentException("unsetState cannot be null when passed to InverseSingleBlockStateMask");
+            }
         }
 
         if (setTypes == 1) {
@@ -321,7 +331,11 @@ public class BlockMask extends ABlockMask {
         }
 
         if (setTypes == totalTypes - 1) {
-            throw new IllegalArgumentException("unsetType cannot be null when passed to InverseSingleBlockTypeMask");
+            if (unsetType != null) {
+                return new InverseSingleBlockTypeMask(getExtent(), unsetType);
+            } else {
+                throw new IllegalArgumentException("unsetType cannot be null when passed to InverseSingleBlockTypeMask");
+            }
         }
 
         return null;
@@ -329,15 +343,15 @@ public class BlockMask extends ABlockMask {
 
     @Override
     public Mask inverse() {
-        boolean[] cloned = ordinals.clone();
+        boolean[] cloned = new boolean[ordinals.length];
         for (int i = 0; i < cloned.length; i++) {
-            cloned[i] = !cloned[i];
+            cloned[i] = !ordinals[i];
         }
         if (replacesAir()) {
-            cloned[1] = false;
+            cloned[BlockTypesCache.ReservedIDs.__RESERVED__] = false;
-            cloned[2] = false;
+            cloned[BlockTypesCache.ReservedIDs.AIR] = false;
-            cloned[3] = false;
+            cloned[BlockTypesCache.ReservedIDs.CAVE_AIR] = false;
-            cloned[0] = false;
+            cloned[BlockTypesCache.ReservedIDs.VOID_AIR] = false;
         }
         return new BlockMask(getExtent(), cloned);
     }

worldedit-core/src/main/java/com/sk89q/worldedit/function/mask/MaskIntersection.java

@@ -163,6 +163,14 @@ public class MaskIntersection extends AbstractMask {
         while (combineMasks(pairingFunction(), failedCombines)) {
             changed = true;
         }
+        if (masks.isEmpty()) {
+            formArray(); // This MaskIntersection instance may be reused for whatever reason, so ensure the array is correct.
+            return Masks.alwaysTrue();
+        }
+        if (masks.size() == 1) {
+            formArray(); // This MaskIntersection instance may be reused for whatever reason, so ensure the array is correct.
+            return masks.iterator().next();
+        }
         // Optimize / combine
         do {
             changed |= optimizeMasks(optimized);