From 53980816dedc1d7403181e950ebe384dc3d4e50b Mon Sep 17 00:00:00 2001
From: Calle Wilund <calle@scylladb.com>
Date: Mon, 10 Jun 2019 14:05:11 +0000
Subject: [PATCH] api.hh: Fix bool parsing in req_param

Fixes #4525

req_param uses boost::lexical cast to convert text->var.
However, lexical_cast does not handle textual booleans,
thus param=true causes not only wrong values, but
exceptions.

Message-Id: <20190610140511.15478-1-calle@scylladb.com>
(cherry picked from commit 26702612f3695af05f2096fe9bdb9cca05d3187d)
---
 api/api.hh | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/api/api.hh b/api/api.hh
index 4eb05e1c91..30d31a63d0 100644
--- a/api/api.hh
+++ b/api/api.hh
@@ -22,6 +22,7 @@
 #pragma once
 
 #include <seastar/json/json_elements.hh>
+#include <type_traits>
 #include <boost/lexical_cast.hpp>
 #include <boost/algorithm/string/split.hpp>
 #include <boost/algorithm/string/classification.hpp>
@@ -231,7 +232,22 @@ public:
             return;
         }
         try {
-            value = T{boost::lexical_cast<Base>(param)};
+            // boost::lexical_cast does not use boolalpha. Converting a
+            // true/false throws exceptions. We don't want that.
+            if constexpr (std::is_same_v<Base, bool>) {
+                // Cannot use boolalpha because we (probably) want to
+                // accept 1 and 0 as well as true and false. And True. And fAlse.
+                std::transform(param.begin(), param.end(), param.begin(), ::tolower);
+                if (param == "true" || param == "1") {
+                    value = T(true);
+                } else if (param == "false" || param == "0") {
+                    value = T(false);
+                } else {
+                    throw boost::bad_lexical_cast{};
+                }
+            } else {
+                value = T{boost::lexical_cast<Base>(param)};
+            }
         } catch (boost::bad_lexical_cast&) {
             throw bad_param_exception(format("{} ({}): type error - should be {}", name, param, boost::units::detail::demangle(typeid(Base).name())));
         }