Merge pull request #4467 from ctiller/DotInHeaderName

Allow . in header names

src/core/transport/metadata.c

@@ -703,7 +703,7 @@ static int conforms_to(grpc_mdstr *s, const gpr_uint8 *legal_bits) {
 
 int grpc_mdstr_is_legal_header(grpc_mdstr *s) {
   static const gpr_uint8 legal_header_bits[256 / 8] = {
-      0x00, 0x00, 0x00, 0x00, 0x00, 0x20, 0xff, 0x03, 0x00, 0x00, 0x00,
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x60, 0xff, 0x03, 0x00, 0x00, 0x00,
       0x80, 0xfe, 0xff, 0xff, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
   return conforms_to(s, legal_header_bits);

tools/codegen/core/gen_legal_metadata_characters.c

@@ -68,6 +68,7 @@ int main(void) {
   for (i = '0'; i <= '9'; i++) legal(i);
   legal('-');
   legal('_');
+  legal('.');
   dump();
 
   clear();