third_party/protobuf: Update to HEAD (f52e188fe4)

third_party/protobuf/csharp/src/Google.Protobuf/JsonFormatter.cs

Index: third_party/protobuf/csharp/src/Google.Protobuf/JsonFormatter.cs
diff --git a/third_party/protobuf/csharp/src/Google.Protobuf/JsonFormatter.cs b/third_party/protobuf/csharp/src/Google.Protobuf/JsonFormatter.cs
index 83772473260dea197a2fd2ee4aa2b8e9bee2caf3..bb1a361e04c5f21b58a78a9b9c5bcf68f6f31638 100644
--- a/third_party/protobuf/csharp/src/Google.Protobuf/JsonFormatter.cs
+++ b/third_party/protobuf/csharp/src/Google.Protobuf/JsonFormatter.cs
@@ -248,80 +248,26 @@ namespace Google.Protobuf
             return !first;
         }
 
-        /// <summary>
-        /// Camel-case converter with added strictness for field mask formatting.
-        /// </summary>
-        /// <exception cref="InvalidOperationException">The field mask is invalid for JSON representation</exception>
-        private static string ToCamelCaseForFieldMask(string input)
-        {
-            for (int i = 0; i < input.Length; i++)
-            {
-                char c = input[i];
-                if (c >= 'A' && c <= 'Z')
-                {
-                    throw new InvalidOperationException($"Invalid field mask to be converted to JSON: {input}");
-                }
-                if (c == '_' && i < input.Length - 1)
-                {
-                    char next = input[i + 1];
-                    if (next < 'a' || next > 'z')
-                    {
-                        throw new InvalidOperationException($"Invalid field mask to be converted to JSON: {input}");
-                    }
-                }
-            }
-            return ToCamelCase(input);
-        }
-
-        // Converted from src/google/protobuf/util/internal/utility.cc ToCamelCase
-        // TODO: Use the new field in FieldDescriptor.
-        internal static string ToCamelCase(string input)
+        // Converted from java/core/src/main/java/com/google/protobuf/Descriptors.java
+        internal static string ToJsonName(string name)
         {
-            bool capitalizeNext = false;
-            bool wasCap = true;
-            bool isCap = false;
-            bool firstWord = true;
-            StringBuilder result = new StringBuilder(input.Length);
-
-            for (int i = 0; i < input.Length; i++, wasCap = isCap)
+            StringBuilder result = new StringBuilder(name.Length);
+            bool isNextUpperCase = false;
+            foreach (char ch in name)
             {
-                isCap = char.IsUpper(input[i]);
-                if (input[i] == '_')
+                if (ch == '_')
                 {
-                    capitalizeNext = true;
-                    if (result.Length != 0)
-                    {
-                        firstWord = false;
-                    }
-                    continue;
+                    isNextUpperCase = true;
                 }
-                else if (firstWord)
+                else if (isNextUpperCase)
                 {
-                    // Consider when the current character B is capitalized,
-                    // first word ends when:
-                    // 1) following a lowercase:   "...aB..."
-                    // 2) followed by a lowercase: "...ABc..."
-                    if (result.Length != 0 && isCap &&
-                        (!wasCap || (i + 1 < input.Length && char.IsLower(input[i + 1]))))
-                    {
-                        firstWord = false;
-                    }
-                    else
-                    {
-                        result.Append(char.ToLowerInvariant(input[i]));
-                        continue;
-                    }
+                    result.Append(char.ToUpperInvariant(ch));
+                    isNextUpperCase = false;
                 }
-                else if (capitalizeNext)
+                else
                 {
-                    capitalizeNext = false;
-                    if (char.IsLower(input[i]))
-                    {
-                        result.Append(char.ToUpperInvariant(input[i]));
-                        continue;
-                    }
+                    result.Append(ch);
                 }
-                result.Append(input[i]);
             }
             return result.ToString();
         }
@@ -377,8 +323,16 @@ namespace Google.Protobuf
                     throw new ArgumentException("Invalid field type");
             }
         }
-        
-        private void WriteValue(TextWriter writer, object value)
+
+        /// <summary>
+        /// Writes a single value to the given writer as JSON. Only types understood by
+        /// Protocol Buffers can be written in this way. This method is only exposed for
+        /// advanced use cases; most users should be using <see cref="Format(IMessage)"/>
+        /// or <see cref="Format(IMessage, TextWriter)"/>.
+        /// </summary>
+        /// <param name="writer">The writer to write the value to. Must not be null.</param>
+        /// <param name="value">The value to write. May be null.</param>
+        public void WriteValue(TextWriter writer, object value)
         {
             if (value == null)
             {
@@ -447,15 +401,7 @@ namespace Google.Protobuf
             }
             else if (value is IMessage)
             {
-                IMessage message = (IMessage) value;
-                if (message.Descriptor.IsWellKnownType)
-                {
-                    WriteWellKnownTypeValue(writer, message.Descriptor, value);
-                }
-                else
-                {
-                    WriteMessage(writer, (IMessage)value);
-                }
+                Format((IMessage)value, writer);
             }
             else
             {
@@ -724,20 +670,6 @@ namespace Google.Protobuf
         }
 
         /// <summary>
-        /// Returns whether or not a singular value can be represented in JSON.
-        /// Currently only relevant for enums, where unknown values can't be represented.
-        /// For repeated/map fields, this always returns true.
-        /// </summary>
-        private bool CanWriteSingleValue(object value)
-        {
-            if (value is System.Enum)
-            {
-                return System.Enum.IsDefined(value.GetType(), value);
-            }
-            return true;
-        }
-
-        /// <summary>
         /// Writes a string (including leading and trailing double quotes) to a builder, escaping as required.
         /// </summary>
         /// <remarks>
@@ -899,6 +831,16 @@ namespace Google.Protobuf
                 return originalName;
             }
 
+#if DOTNET35
+            // TODO: Consider adding functionality to TypeExtensions to avoid this difference.
+            private static Dictionary<object, string> GetNameMapping(System.Type enumType) =>
+                enumType.GetFields(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Static)
+                    .ToDictionary(f => f.GetValue(null),
+                                  f => (f.GetCustomAttributes(typeof(OriginalNameAttribute), false)
+                                        .FirstOrDefault() as OriginalNameAttribute)
+                                        // If the attribute hasn't been applied, fall back to the name of the field.
+                                        ?.Name ?? f.Name);
+#else
             private static Dictionary<object, string> GetNameMapping(System.Type enumType) =>
                 enumType.GetTypeInfo().DeclaredFields
                     .Where(f => f.IsStatic)
@@ -907,6 +849,7 @@ namespace Google.Protobuf
                                         .FirstOrDefault()
                                         // If the attribute hasn't been applied, fall back to the name of the field.
                                         ?.Name ?? f.Name);
+#endif
         }
     }
 }