Fixing bug with range ignore + regions (#1216)

Src/CSharpier.Tests/FormattingTests/TestFiles/cs/Directives_Regions.test

@@ -40,3 +40,12 @@ public class ClassName
         #endregion one
     ;
 }
+
+class ClassName
+{
+    #region Region
+    // csharpier-ignore-start
+    public string   Field;
+    // csharpier-ignore-end
+    #endregion
+}

Src/CSharpier/DocPrinter/DocPrinter.cs

@@ -14,7 +14,7 @@ internal class DocPrinter
     protected readonly string EndOfLine;
     protected readonly PrinterOptions PrinterOptions;
     protected readonly Indenter Indenter;
-    protected Stack<Indent> RegionIndents = new();
+    protected readonly Stack<Indent> RegionIndents = new();
 
     protected DocPrinter(Doc doc, PrinterOptions printerOptions, string endOfLine)
     {
@@ -156,8 +156,17 @@ private void ProcessNextCommand()
         {
             if (region.IsEnd)
             {
-                var regionIndent = this.RegionIndents.Pop();
-                this.Output.Append(regionIndent.Value);
+                // in the case where regions are combined with ignored ranges, the start region
+                // ends up printing inside the unformatted nodes, so we don't have a matching
+                // start region to go with this end region
+                if (this.RegionIndents.TryPop(out var regionIndent))
+                {
+                    this.Output.Append(regionIndent.Value);
+                }
+                else
+                {
+                    this.Output.Append(indent.Value);
+                }
             }
             else
             {

Src/CSharpier/Utilities/StackExtensions.cs

@@ -0,0 +1,22 @@
+namespace CSharpier.Utilities;
+
+using System.Diagnostics.CodeAnalysis;
+
+internal static class StackExtensions
+{
+#if NETSTANDARD2_0
+    public static bool TryPop<T>(this Stack<T> stack, [NotNullWhen(true)] out T? result)
+    {
+        if (stack.Count > 0)
+        {
+            result = stack.Pop()!;
+            return true;
+        }
+        else
+        {
+            result = default;
+            return false;
+        }
+    }
+#endif
+}