.

Author: SimonCropp

src/ApiBuilderTests/FrameworkSplitterTest.cs

@@ -213,6 +213,15 @@ static string SimplifyConditionLine(string line, List<string> definedSymbols)
 
     static string SimplifyCondition(string condition, List<string> definedSymbols)
     {
+        // Only simplify simple patterns to avoid breaking complex nested expressions
+        // For complex conditions with nested parentheses or ||, return as-is
+
+        // If condition contains || or nested parentheses, don't try to simplify
+        if (condition.Contains("||") || ContainsNestedParentheses(condition))
+        {
+            return condition;
+        }
+
         var result = condition;
 
         // Build a set of all framework-related symbols (both defined and potentially undefined)
@@ -237,31 +246,28 @@ static string SimplifyCondition(string condition, List<string> definedSymbols)
         var definedSet = definedSymbols.ToHashSet();
 
         // For each framework symbol, simplify based on whether it's defined
+        // Only handle simple "SYMBOL && rest" or "rest && SYMBOL" patterns without parentheses
         foreach (var symbol in allFrameworkSymbols)
         {
             var isDefined = definedSet.Contains(symbol);
 
             if (isDefined)
             {
-                // Symbol is defined (true)
-                // !SYMBOL is false - if part of &&, whole thing might be false (but BranchTaken would handle that)
-                // SYMBOL is true - can be removed from && chains
-                // Remove "SYMBOL && " or " && SYMBOL" patterns
-                result = System.Text.RegularExpressions.Regex.Replace(result, $@"\b{symbol}\b\s*&&\s*", "");
-                result = System.Text.RegularExpressions.Regex.Replace(result, $@"\s*&&\s*\b{symbol}\b", "");
-                // Handle standalone SYMBOL (entire condition is just the symbol)
+                // Symbol is defined (true) - can be removed from simple && chains
+                // Only match if not inside parentheses
+                result = System.Text.RegularExpressions.Regex.Replace(result, $@"^\s*\b{symbol}\b\s*&&\s*", "");
+                result = System.Text.RegularExpressions.Regex.Replace(result, $@"\s*&&\s*\b{symbol}\b\s*$", "");
+                // Handle standalone SYMBOL
                 if (result.Trim() == symbol)
                 {
                     result = "true";
                 }
             }
             else
             {
-                // Symbol is not defined (false)
-                // !SYMBOL is true - can be removed from && chains
-                // Remove "!SYMBOL && " or " && !SYMBOL" patterns
-                result = System.Text.RegularExpressions.Regex.Replace(result, $@"!\s*{symbol}\s*&&\s*", "");
-                result = System.Text.RegularExpressions.Regex.Replace(result, $@"\s*&&\s*!\s*{symbol}\b", "");
+                // Symbol is not defined (false) - !SYMBOL is true, can be removed from simple && chains
+                result = System.Text.RegularExpressions.Regex.Replace(result, $@"^\s*!\s*\b{symbol}\b\s*&&\s*", "");
+                result = System.Text.RegularExpressions.Regex.Replace(result, $@"\s*&&\s*!\s*\b{symbol}\b\s*$", "");
                 // Handle standalone !SYMBOL
                 if (System.Text.RegularExpressions.Regex.IsMatch(result.Trim(), $@"^!\s*{symbol}$"))
                 {
@@ -273,6 +279,18 @@ static string SimplifyCondition(string condition, List<string> definedSymbols)
         return result.Trim();
     }
 
+    static bool ContainsNestedParentheses(string condition)
+    {
+        var depth = 0;
+        foreach (var c in condition)
+        {
+            if (c == '(') depth++;
+            else if (c == ')') depth--;
+            if (depth > 1) return true;
+        }
+        return false;
+    }
+
     // Symbols to define during parsing (makes code active)
     // Excludes symbols that typically appear negated (like !RefsBclMemory)
     List<string> GetParseSymbols() =>

src/Split/net461/Polyfill_Memory_SpanSplitEnumerator.cs

@@ -1,6 +1,6 @@
 // <auto-generated />
 #pragma warning disable
-#if FeatureMemory && FeatureValueTuple
+#if FeatureMemory && !NET9_0_OR_GREATER && FeatureValueTuple
 
 namespace Polyfills;
 

src/Split/net461/Polyfill_Stream_Read.cs

@@ -9,7 +9,7 @@ namespace Polyfills;
 
 static partial class Polyfill
 {
-#if (!NETCOREAPP2_1_OR_GREATER) && FeatureMemory
+#if (!NETCOREAPP2_1_OR_GREATER && !NETSTANDARD2_1) && FeatureMemory
     /// <summary>
     /// Reads a sequence of bytes from the current stream and advances the position within the stream by the number of bytes read.
     /// </summary>

src/Split/net461/Polyfill_StringBuilder.cs

@@ -1,6 +1,6 @@
 // <auto-generated />
 #pragma warning disable
-#if FeatureMemory && (!NETSTANDARD2_1_OR_GREATER)
+#if FeatureMemory && (!NETSTANDARD2_1_OR_GREATER && !NETCOREAPP2_1_OR_GREATER)
 
 namespace Polyfills;
 

src/Split/net461/Polyfill_StringBuilder_Append.cs

@@ -34,7 +34,7 @@ public static StringBuilder Append(this StringBuilder target, StringBuilder? val
     }
 
 
-#if FeatureMemory && (!NETSTANDARD2_1_OR_GREATER)
+#if FeatureMemory && (!NETSTANDARD2_1_OR_GREATER && !NETCOREAPP2_1_OR_GREATER)
 
     /// <summary>
     /// Appends the string representation of a specified read-only character span to this instance.

src/Split/net461/Polyfill_StringBuilder_CopyTo.cs

@@ -1,6 +1,6 @@
 // <auto-generated />
 #pragma warning disable
-#if FeatureMemory && (!NETSTANDARD2_1_OR_GREATER)
+#if FeatureMemory && (!NETSTANDARD2_1_OR_GREATER && !NETCOREAPP2_1_OR_GREATER)
 
 namespace Polyfills;
 

src/Split/net461/Polyfill_TextReader.cs

@@ -10,7 +10,7 @@ namespace Polyfills;
 
 static partial class Polyfill
 {
-#if FeatureValueTask && FeatureMemory
+#if FeatureValueTask && FeatureMemory && !NETCOREAPP3_0_OR_GREATER
     /// <summary>
     /// Asynchronously reads the characters from the current stream into a memory block.
     /// </summary>

src/Split/net461/ZipArchiveEntryPolyfill.cs

@@ -1,6 +1,6 @@
 // <auto-generated />
 #pragma warning disable
-#if FeatureCompression && ((!NET472_OR_GREATER) || NETSTANDARD2_0)
+#if FeatureCompression && ((NETFRAMEWORK && !NET472_OR_GREATER) || NETSTANDARD2_0)
 namespace Polyfills;
 
 using System.IO.Compression;

src/Split/net462/Polyfill_Memory_SpanSplitEnumerator.cs

@@ -1,6 +1,6 @@
 // <auto-generated />
 #pragma warning disable
-#if FeatureMemory && FeatureValueTuple
+#if FeatureMemory && !NET9_0_OR_GREATER && FeatureValueTuple
 
 namespace Polyfills;
 

src/Split/net462/Polyfill_Stream_Read.cs

@@ -9,7 +9,7 @@ namespace Polyfills;
 
 static partial class Polyfill
 {
-#if (!NETCOREAPP2_1_OR_GREATER) && FeatureMemory
+#if (!NETCOREAPP2_1_OR_GREATER && !NETSTANDARD2_1) && FeatureMemory
     /// <summary>
     /// Reads a sequence of bytes from the current stream and advances the position within the stream by the number of bytes read.
     /// </summary>