Accept -nan per the RESP3 spec recommendation.

For reference:
https://github.com/redis/redis-specifications/blob/master/protocol/RESP3.md

2 files changed, 12 insertions, 1 deletions

diff --git a/read.c b/read.c
index 8e6d21b..9c8f869 100644
--- a/read.c
+++ b/read.c
@@ -303,7 +303,8 @@ static int processLineItem(redisReader *r) {
                 d = INFINITY; /* Positive infinite. */
             } else if (len == 4 && strcasecmp(buf,"-inf") == 0) {
                 d = -INFINITY; /* Negative infinite. */
-            } else if (len == 3 && strcasecmp(buf,"nan") == 0) {
+            } else if ((len == 3 && strcasecmp(buf,"nan") == 0) ||
+                       (len == 4 && strcasecmp(buf, "-nan") == 0)) {
                 d = NAN; /* nan. */
             } else {
                 d = strtod((char*)buf,&eptr);
diff --git a/test.c b/test.c
index c1065ff..77e7f1a 100644
--- a/test.c
+++ b/test.c
@@ -684,6 +684,16 @@ static void test_reply_reader(void) {
     freeReplyObject(reply);
     redisReaderFree(reader);
 
+    test("Correctly parses RESP3 double -Nan: ");
+    reader = redisReaderCreate();
+    redisReaderFeed(reader, ",-nan\r\n", 7);
+    ret = redisReaderGetReply(reader, &reply);
+    test_cond(ret == REDIS_OK &&
+              ((redisReply*)reply)->type == REDIS_REPLY_DOUBLE &&
+              isnan(((redisReply*)reply)->dval));
+    freeReplyObject(reply);
+    redisReaderFree(reader);
+
     test("Can parse RESP3 nil: ");
     reader = redisReaderCreate();
     redisReaderFeed(reader, "_\r\n",3);