Added support for NaN and infinity in JsonBuilder in double and ascii number interfaces.

fdbclient/JsonString.cpp

@@ -29,6 +29,16 @@ int JsonBuilder::coerceAsciiNumberToJSON(const char *s, int len, char *dst) {
 		}
 	}
 
+	// 'inf' becomes 1e99
+	if(*s == 'i') {
+		if(len >= 3 && (strncmp(s, "inf", 3) == 0)) {
+			strcpy(wptr, "1e99");
+			return 4 + wptr - dst;
+		}
+		// Anything else starting with 'i' is a failure
+		return 0;
+	}
+
 	// Skip leading zeroes
 	while(*s == '0') {
 		++s;

fdbclient/JsonString.h

@@ -2,6 +2,7 @@
 
 #include <string>
 #include <vector>
+#include <cmath>
 #include "flow/flow.h"
 #include "flow/Trace.h"
 #include "fdbrpc/JSONDoc.h"
@@ -125,7 +126,15 @@ protected:
 	}
 
 	void writeValue(const double& val) {
-		writeFormat("%g", val);
+		if(std::isfinite(val)) {
+			writeFormat("%g", val);
+		}
+		else if(std::isnan(val)) {
+			write("-999");
+		}
+		else {
+			write("1e99");
+		}
 	}
 
 	bool shouldEscape(char c) {

fdbserver/Status.actor.cpp

@@ -2041,6 +2041,17 @@ TEST_CASE("status/json/builder") {
 	array2.addContents(JsonBuilderArray());
 	ASSERT(checkJson(array2, "[null,1,2,\"test\"]"));
 
+	JsonBuilderObject object3;
+	object3["infinity"] = std::numeric_limits<double>::infinity();
+	object3["nan"] = std::numeric_limits<double>::quiet_NaN();
+	ASSERT(checkJson(object3, "{\"infinity\":1e99,\"nan\":-999}"));
+
+	ASSERT(checkAsciiNumber("inf"));
+	ASSERT(checkAsciiNumber("infA"));
+	ASSERT(checkAsciiNumber("in"));
+	ASSERT(checkAsciiNumber("-inf"));
+	ASSERT(checkAsciiNumber("-infA"));
+	ASSERT(checkAsciiNumber("-in"));
 	ASSERT(checkAsciiNumber("a"));
 	ASSERT(checkAsciiNumber("-1a.0"));
 	ASSERT(checkAsciiNumber("-01a.0"));