Merge pull request #496 from bernardo-bruning/fix-json-enconde-negative-hours

Fix negative hours when encode to JSON

tests/BUILD

@@ -83,6 +83,7 @@ proto_library(
     srcs = [
         "test_cpp.proto",
     ],
+    deps = ["@com_google_protobuf//:timestamp_proto"]
 )
 
 upb_proto_library(

tests/test_cpp.cc

@@ -38,6 +38,8 @@
 #include "gtest/gtest.h"
 #include "tests/test_cpp.upb.h"
 #include "tests/test_cpp.upbdefs.h"
+#include "google/protobuf/timestamp.upb.h"
+#include "google/protobuf/timestamp.upbdefs.h"
 #include "upb/def.h"
 #include "upb/def.hpp"
 #include "upb/json_decode.h"
@@ -148,3 +150,33 @@ TEST(Cpp, JsonNull) {
   EXPECT_EQ(0, strcmp(str_f.default_value().str_val.data, "abc"));
   EXPECT_EQ(3, str_f.default_value().str_val.size);
 }
+
+TEST(Cpp, TimestampEncoder) {
+  upb::SymbolTable symtab;
+  upb::Arena arena;
+  upb::MessageDefPtr md(google_protobuf_Timestamp_getmsgdef(symtab.ptr()));
+  google_protobuf_Timestamp* timestamp_upb = google_protobuf_Timestamp_new(arena.ptr());
+  google_protobuf_Timestamp* timestamp_upb_decoded = google_protobuf_Timestamp_new(arena.ptr());
+
+
+  long timestamps[] = {
+    253402300799,	// 9999-12-31T23:59:59Z
+    1641006000,		// 2022-01-01T03:00:00Z
+    0,			// 1970-01-01T00:00:00Z
+    -31525200,		// 1969-01-01T03:00:00Z
+    -2208988800,	// 1900-01-01T00:00:00Z
+    -62135596800,	// 0000-01-01T00:00:00Z
+  };
+
+  for(long timestamp: timestamps) {
+    google_protobuf_Timestamp_set_seconds(timestamp_upb, timestamp);
+
+    char json[128];
+    size_t size = upb_JsonEncode(timestamp_upb, md.ptr(), NULL, 0, json, sizeof(json), NULL);
+    bool result = upb_JsonDecode(json, size, timestamp_upb_decoded, md.ptr(), NULL, 0, arena.ptr(), NULL);
+    const long timestamp_decoded = google_protobuf_Timestamp_seconds(timestamp_upb_decoded); 
+
+    ASSERT_TRUE(result);
+    EXPECT_EQ(timestamp, timestamp_decoded);
+  }
+}

upb/json_encode.c

@@ -162,7 +162,8 @@ static void jsonenc_timestamp(jsonenc* e, const upb_Message* msg,
    * Fliegel, H. F., and Van Flandern, T. C., "A Machine Algorithm for
    *   Processing Calendar Dates," Communications of the Association of
    *   Computing Machines, vol. 11 (1968), p. 657.  */
-  L = (int)(seconds / 86400) + 68569 + 2440588;
+  seconds += 62135596800; // Ensure seconds is positive. 
+  L = (int)(seconds / 86400) - 719162 + 68569 + 2440588;
   N = 4 * L / 146097;
   L = L - (146097 * N + 3) / 4;
   I = 4000 * (L + 1) / 1461001;