From 775a235880b9c30ca988a93b088bdb11642f08dd Mon Sep 17 00:00:00 2001
From: Lars Melchior <TheLartians@users.noreply.github.com>
Date: Thu, 6 Feb 2020 11:50:55 +0100
Subject: [PATCH] default to "ON" for options without explicit value definition
 (#96)

* default to "ON" for options without explicit value definition

* increment CPM version

* compare the correct lengths
---
 cmake/CPM.cmake               | 12 +++++++++---
 examples/gtest/CMakeLists.txt |  2 +-
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/cmake/CPM.cmake b/cmake/CPM.cmake
index a6e9301..6b787ef 100644
--- a/cmake/CPM.cmake
+++ b/cmake/CPM.cmake
@@ -28,7 +28,7 @@
 
 cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 
-set(CURRENT_CPM_VERSION 0.15.1)
+set(CURRENT_CPM_VERSION 0.16)
 
 if(CPM_DIRECTORY)
   if(NOT ${CPM_DIRECTORY} MATCHES ${CMAKE_CURRENT_LIST_DIR})
@@ -303,9 +303,15 @@ endfunction()
 # splits a package option
 function(cpm_parse_option OPTION)
   string(REGEX MATCH "^[^ ]+" OPTION_KEY ${OPTION})
+  string(LENGTH ${OPTION} OPTION_LENGTH)
   string(LENGTH ${OPTION_KEY} OPTION_KEY_LENGTH)
-  math(EXPR OPTION_KEY_LENGTH "${OPTION_KEY_LENGTH}+1")
-  string(SUBSTRING ${OPTION} "${OPTION_KEY_LENGTH}" "-1" OPTION_VALUE)
+  if (OPTION_KEY_LENGTH STREQUAL OPTION_LENGTH)
+    # no value for key provided, assume user wants to set option to "ON"
+    set(OPTION_VALUE "ON")
+  else()
+    math(EXPR OPTION_KEY_LENGTH "${OPTION_KEY_LENGTH}+1")
+    string(SUBSTRING ${OPTION} "${OPTION_KEY_LENGTH}" "-1" OPTION_VALUE)
+  endif()
   set(OPTION_KEY "${OPTION_KEY}" PARENT_SCOPE)
   set(OPTION_VALUE "${OPTION_VALUE}" PARENT_SCOPE)
 endfunction()
diff --git a/examples/gtest/CMakeLists.txt b/examples/gtest/CMakeLists.txt
index 2f82742..32ed2a7 100644
--- a/examples/gtest/CMakeLists.txt
+++ b/examples/gtest/CMakeLists.txt
@@ -23,7 +23,7 @@ CPMAddPackage(
   VERSION 1.8.1
   OPTIONS
       "INSTALL_GTEST OFF"
-      "gtest_force_shared_crt ON"
+      "gtest_force_shared_crt"
 )
 
 # ---- Create binary ----