Bug: Fix occasional unsafe brace removing with nested ifs.

Author: DeanEdisGG

ShaderShrinker/Shrinker.Lexer/StringExtensions.cs

@@ -48,11 +48,14 @@ public static int GetCodeCharCount(this string glsl)
 
         public static bool IsNewline(this char ch) => ch == '\n' || ch == '\r';
 
+        /// <summary>
+        /// Remove start/end braces if the content is a single-line instruction.
+        /// </summary>
         public static string AllowBraceRemoval(this string s)
         {
             s = s.Trim();
             if (s.StartsWith("{") && s.EndsWith("}") && s.Count(ch => ch == ';') == 1)
-                return s.Trim('{', '}', ' ');
+                return s.Substring(1, s.Length - 2).Trim();
             return s;
         }
 

ShaderShrinker/Shrinker.Parser/GlslOutputFormatter.cs

@@ -328,7 +328,9 @@ o.Parent is not VariableDeclarationSyntaxNode && // ...not defined in within a d
 
                     var braceCode = new StringBuilder();
                     AppendCode(braceCode, o.TrueBranch);
-                    var trueBranch = braceCode.ToString().AllowBraceRemoval();
+                    var trueBranch = braceCode.ToString();
+                    if (o.TrueBranch.Children.FirstOrDefault() is not IfSyntaxNode || o.FalseBranch == null)
+                        trueBranch = trueBranch.AllowBraceRemoval();
                     sb.AppendLine(trueBranch);
 
                     if (o.FalseBranch != null)

ShaderShrinker/UnitTests/ShrinkerTests.cs

@@ -1844,6 +1844,19 @@ public void CheckStatementBracketsNotRemovedWhenSimplifyingArithmetic(
             Assert.That(rootNode.ToCode().ToSimple(), Is.EqualTo(code));
         }
 
+        [Test]
+        public void CheckBracesNotRemovedInIfWithNestedIf()
+        {
+            var lexer = new Lexer();
+            lexer.Load("int main() { if (true) { if (false) return 1; } else { return 2; } }");
+
+            var rootNode = new Parser(lexer)
+                .Parse()
+                .Simplify(CustomOptions.None());
+
+            Assert.That(rootNode.ToCode().ToSimple(), Is.EqualTo("int main() { if (true) { if (false) return 1; } else return 2; }"));
+        }
+
         [Test]
         public void CheckSupportForTernaryOperator()
         {