From 1644c0dd87f40a2492bde4011fe72257fc72ee0e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Julius=20Br=C3=BCggemann?= <julius9402@gmail.com>
Date: Mon, 29 Mar 2021 19:57:08 +0200
Subject: [PATCH] Add CMake option for building with ZLib

---
 CMakeLists.txt | 29 +++++++++++++++++------------
 INSTALL.md     |  7 +++++++
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index fe1ef8c0..309f000b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -93,20 +93,25 @@ math(EXPR TAGLIB_SOVERSION_PATCH "${TAGLIB_SOVERSION_REVISION}")
 include(ConfigureChecks.cmake)
 
 # Determine whether zlib is installed.
+option(WITH_ZLIB "Build with ZLIB" ON)
 
-if(NOT ZLIB_SOURCE)
-  find_package(ZLIB)
-  if(ZLIB_FOUND)
-    set(HAVE_ZLIB 1)
-    set(ZLIB_LIBRARIES_FLAGS -lz)
-  else()
-    set(HAVE_ZLIB 0)
+if(WITH_ZLIB)
+  if(NOT ZLIB_SOURCE)
+    find_package(ZLIB)
+    if(ZLIB_FOUND)
+      set(HAVE_ZLIB 1)
+      set(ZLIB_LIBRARIES_FLAGS -lz)
+    else()
+      set(HAVE_ZLIB 0)
+    endif()
   endif()
-endif()
-
-if(NOT HAVE_ZLIB AND ZLIB_SOURCE)
-  set(HAVE_ZLIB 1)
-  set(HAVE_ZLIB_SOURCE 1)
+  
+  if(NOT HAVE_ZLIB AND ZLIB_SOURCE)
+    set(HAVE_ZLIB 1)
+    set(HAVE_ZLIB_SOURCE 1)
+  endif()
+else()
+  set(HAVE_ZLIB 0)
 endif()
 
 if(NOT WIN32)
diff --git a/INSTALL.md b/INSTALL.md
index 25686d5b..4e7d61e9 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -13,6 +13,12 @@ In order to build the included examples, use the `BUILD_EXAMPLES` option:
 
     cmake -DBUILD_EXAMPLES=ON [...]
 
+If you want to build TagLib without ZLib, you can use
+
+    cmake -DCMAKE_INSTALL_PREFIX=/usr/local -DCMAKE_BUILD_TYPE=Release -DWITH_ZLIB=OFF .
+    make
+    sudo make install
+
 See http://www.cmake.org/cmake/help/runningcmake.html for generic help on
 running CMake.
 
@@ -74,6 +80,7 @@ Useful configuration options used with CMake (GUI and/or command line):
 
   | option                  | description |
   | ----------------------- | ----------- |
+  | `WITH_ZLIB=`            | Whether to build with ZLib |
   | `ZLIB_ROOT=`            | Where to find ZLib's root directory. Assumes parent of: `\include` and `\lib.`|
   | `ZLIB_INCLUDE_DIR=`     | Where to find ZLib's Include directory.|
   | `ZLIB_LIBRARY=`         | Where to find ZLib's Library.