From b164dc699bedd09483691a6ed4133aacf4e8d4a3 Mon Sep 17 00:00:00 2001
From: xiangchen02 <18351967270@163.com>
Date: Mon, 3 Mar 2025 20:50:44 +0800
Subject: [PATCH 1/2] fix CScript string.compare

Because the default compare sorting rules of c# string are different from those of cpp, the binary file exported by flatc -b cannot use LookupByKey
---
 src/idl_gen_csharp.cpp | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/src/idl_gen_csharp.cpp b/src/idl_gen_csharp.cpp
index 9988523f32f..0b644c2abc9 100644
--- a/src/idl_gen_csharp.cpp
+++ b/src/idl_gen_csharp.cpp
@@ -620,12 +620,22 @@ class CSharpGenerator : public BaseGenerator {
   std::string GenKeyGetter(flatbuffers::StructDef &struct_def,
                            flatbuffers::FieldDef *key_field) const {
     // Get the getter for the key of the struct.
-    return GenGetterForLookupByKey(struct_def, key_field, "builder.DataBuffer",
-                                   "builder.DataBuffer.Length - o1.Value") +
-           ".CompareTo(" +
-           GenGetterForLookupByKey(struct_def, key_field, "builder.DataBuffer",
-                                   "builder.DataBuffer.Length - o2.Value") +
-           ")";
+    if (IsString(key_field->value.type)) {
+      return "string.CompareOrdinal(" +
+         GenGetterForLookupByKey(struct_def, key_field, "builder.DataBuffer", 
+           "builder.DataBuffer.Length - o1.Value") +
+         ", " +
+         GenGetterForLookupByKey(struct_def, key_field, "builder.DataBuffer",
+           "builder.DataBuffer.Length - o2.Value") + 
+         ")";
+    } else {
+      return GenGetterForLookupByKey(struct_def, key_field, "builder.DataBuffer",
+                     "builder.DataBuffer.Length - o1.Value") +
+         ".CompareTo(" +
+         GenGetterForLookupByKey(struct_def, key_field, "builder.DataBuffer", 
+                     "builder.DataBuffer.Length - o2.Value") +
+         ")";
+    }
   }
 
   // Get the value of a table verification function start
@@ -1539,7 +1549,11 @@ class CSharpGenerator : public BaseGenerator {
           "(start + middle), bb);\n";
 
       code += "      obj_.__assign(tableOffset, bb);\n";
-      code += "      int comp = obj_." + name + ".CompareTo(key);\n";
+      if (IsString(key_field->value.type)) {
+        code += "      int comp = string.CompareOrdinal(obj_." + name + ", key);\n";
+      } else {
+        code += "      int comp = obj_." + name + ".CompareTo(key);\n";
+      }
       code += "      if (comp > 0) {\n";
       code += "        span = middle;\n";
       code += "      } else if (comp < 0) {\n";

From 03df77399149985c1a95dcb6b8727a1ac919a6d0 Mon Sep 17 00:00:00 2001
From: xiangchen02 <18351967270@163.com>
Date: Mon, 3 Mar 2025 21:02:18 +0800
Subject: [PATCH 2/2] run generate_code.py

---
 tests/MyGame/Example/Monster.cs                               | 4 ++--
 tests/union_value_collsion/union_value_collision_generated.cs | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/MyGame/Example/Monster.cs b/tests/MyGame/Example/Monster.cs
index 17327798208..46abfd09401 100644
--- a/tests/MyGame/Example/Monster.cs
+++ b/tests/MyGame/Example/Monster.cs
@@ -521,7 +521,7 @@ public struct Monster : IFlatbufferObject
   public static VectorOffset CreateSortedVectorOfMonster(FlatBufferBuilder builder, Offset<Monster>[] offsets) {
     Array.Sort(offsets,
       (Offset<Monster> o1, Offset<Monster> o2) =>
-        new Monster().__assign(builder.DataBuffer.Length - o1.Value, builder.DataBuffer).Name.CompareTo(new Monster().__assign(builder.DataBuffer.Length - o2.Value, builder.DataBuffer).Name));
+        string.CompareOrdinal(new Monster().__assign(builder.DataBuffer.Length - o1.Value, builder.DataBuffer).Name, new Monster().__assign(builder.DataBuffer.Length - o2.Value, builder.DataBuffer).Name));
     return builder.CreateVectorOfTables(offsets);
   }
 
@@ -533,7 +533,7 @@ public static VectorOffset CreateSortedVectorOfMonster(FlatBufferBuilder builder
       int middle = span / 2;
       int tableOffset = Table.__indirect(vectorLocation + 4 * (start + middle), bb);
       obj_.__assign(tableOffset, bb);
-      int comp = obj_.Name.CompareTo(key);
+      int comp = string.CompareOrdinal(obj_.Name, key);
       if (comp > 0) {
         span = middle;
       } else if (comp < 0) {
diff --git a/tests/union_value_collsion/union_value_collision_generated.cs b/tests/union_value_collsion/union_value_collision_generated.cs
index f4686997f31..927183637a8 100644
--- a/tests/union_value_collsion/union_value_collision_generated.cs
+++ b/tests/union_value_collsion/union_value_collision_generated.cs
@@ -292,7 +292,7 @@ public struct Collide : IFlatbufferObject
   public static VectorOffset CreateSortedVectorOfCollide(FlatBufferBuilder builder, Offset<Collide>[] offsets) {
     Array.Sort(offsets,
       (Offset<Collide> o1, Offset<Collide> o2) =>
-        new Collide().__assign(builder.DataBuffer.Length - o1.Value, builder.DataBuffer).Collide_.CompareTo(new Collide().__assign(builder.DataBuffer.Length - o2.Value, builder.DataBuffer).Collide_));
+        string.CompareOrdinal(new Collide().__assign(builder.DataBuffer.Length - o1.Value, builder.DataBuffer).Collide_, new Collide().__assign(builder.DataBuffer.Length - o2.Value, builder.DataBuffer).Collide_));
     return builder.CreateVectorOfTables(offsets);
   }
 
@@ -304,7 +304,7 @@ public static VectorOffset CreateSortedVectorOfCollide(FlatBufferBuilder builder
       int middle = span / 2;
       int tableOffset = Table.__indirect(vectorLocation + 4 * (start + middle), bb);
       obj_.__assign(tableOffset, bb);
-      int comp = obj_.Collide_.CompareTo(key);
+      int comp = string.CompareOrdinal(obj_.Collide_, key);
       if (comp > 0) {
         span = middle;
       } else if (comp < 0) {