Replace zlib dependency by miniz single header library.

I've chosen the minimal invasive way for this:

  * Import miniz and remove -lz linker flags.
  * Create a short header minizconf.h roviding everything we need
    originally defined by zconf.h and not provided by miniz.
  * Replace zlib.h with miniz.h and minizconf.h.

CMakeLists.txt

@@ -95,9 +95,6 @@ if(${CMAKE_HOST_SYSTEM_NAME} STREQUAL "FreeBSD")
 endif()
 
 if(${ZIP_SUPPORT})
-	find_package(ZLIB REQUIRED)
-	list(APPEND yquake2IncludeDirectories ${ZLIB_INCLUDE_DIRS})
-	list(APPEND yquake2ZLibLinkerFlags ${ZLIB_LIBRARIES})
 	add_definitions(-DZIP -DNOUNCRYPT)
 
 	if(NOT CMAKE_SYSTEM_NAME MATCHES "Linux" OR NOT CMAKE_SYSTEM_NAME MATCHES "Windows")
@@ -332,6 +329,7 @@ set(Client-Source
 	${COMMON_SRC_DIR}/shared/rand.c
 	${COMMON_SRC_DIR}/shared/shared.c
 	${COMMON_SRC_DIR}/unzip/ioapi.c
+	${COMMON_SRC_DIR}/unzip/miniz.c
 	${COMMON_SRC_DIR}/unzip/unzip.c
 	${SERVER_SRC_DIR}/sv_cmd.c
 	${SERVER_SRC_DIR}/sv_conless.c
@@ -367,6 +365,8 @@ set(Client-Header
 	${COMMON_SRC_DIR}/header/shared.h
 	${COMMON_SRC_DIR}/header/zone.h
 	${COMMON_SRC_DIR}/unzip/ioapi.h
+	${COMMON_SRC_DIR}/unzip/miniz.h
+	${COMMON_SRC_DIR}/unzip/minizconf.h
 	${COMMON_SRC_DIR}/unzip/unzip.h
 	${SERVER_SRC_DIR}/header/server.h
 	)
@@ -390,6 +390,7 @@ set(Server-Source
 	${COMMON_SRC_DIR}/shared/rand.c
 	${COMMON_SRC_DIR}/shared/shared.c
 	${COMMON_SRC_DIR}/unzip/ioapi.c
+	${COMMON_SRC_DIR}/unzip/miniz.c
 	${COMMON_SRC_DIR}/unzip/unzip.c
 	${SERVER_SRC_DIR}/sv_cmd.c
 	${SERVER_SRC_DIR}/sv_conless.c
@@ -411,6 +412,8 @@ set(Server-Header
 	${COMMON_SRC_DIR}/header/shared.h
 	${COMMON_SRC_DIR}/header/zone.h
 	${COMMON_SRC_DIR}/unzip/ioapi.h
+	${COMMON_SRC_DIR}/unzip/miniz.h
+	${COMMON_SRC_DIR}/unzip/minizconf.h
 	${COMMON_SRC_DIR}/unzip/unzip.h
 	${SERVER_SRC_DIR}/header/server.h
 	)

Makefile

@@ -347,7 +347,6 @@ endif
 
 ifeq ($(WITH_ZIP),yes)
 release/yquake2.exe : CFLAGS += -DZIP -DNOUNCRYPT
-release/yquake2.exe : LDFLAGS += -lz
 endif
 
 release/yquake2.exe : LDFLAGS += -mwindows
@@ -399,7 +398,6 @@ endif # WITH_OPENAL
 
 ifeq ($(WITH_ZIP),yes)
 release/quake2 : CFLAGS += $(ZIPCFLAGS) -DZIP -DNOUNCRYPT
-release/quake2 : LDFLAGS += -lz
 endif
 
 ifeq ($(YQ2_OSTYPE), FreeBSD)
@@ -440,11 +438,9 @@ build/server/%.o: %.c
 	${Q}$(CC) -c $(CFLAGS) $(INCLUDE) -o $@ $<
 
 release/q2ded.exe : CFLAGS += -DDEDICATED_ONLY
-release/q2ded.exe : LDFLAGS += -lz
 
 ifeq ($(WITH_ZIP),yes)
 release/q2ded.exe : CFLAGS += -DZIP -DNOUNCRYPT
-release/q2ded.exe : LDFLAGS += -lz
 endif
 else # not Windows
 server:
@@ -461,7 +457,6 @@ release/q2ded : CFLAGS += -DDEDICATED_ONLY -Wno-unused-result
 
 ifeq ($(WITH_ZIP),yes)
 release/q2ded : CFLAGS += $(ZIPCFLAGS) -DZIP -DNOUNCRYPT
-release/q2ded : LDFLAGS += -lz
 endif
 
 ifeq ($(YQ2_OSTYPE), FreeBSD)
@@ -734,6 +729,7 @@ CLIENT_OBJS_ := \
 	src/common/shared/rand.o \
 	src/common/shared/shared.o \
 	src/common/unzip/ioapi.o \
+	src/common/unzip/miniz.o \
 	src/common/unzip/unzip.o \
 	src/server/sv_cmd.o \
 	src/server/sv_conless.o \
@@ -885,6 +881,7 @@ SERVER_OBJS_ := \
 	src/common/shared/rand.o \
 	src/common/shared/shared.o \
 	src/common/unzip/ioapi.o \
+	src/common/unzip/miniz.o \
 	src/common/unzip/unzip.o \
 	src/server/sv_cmd.o \
 	src/server/sv_conless.o \

src/client/vid/vid.c

@@ -39,7 +39,7 @@
 // If we build with zip support, zlib is available and
 // we can use that for better PNG compression.
 
-#include <zlib.h>
+#include "../../common/unzip/miniz.h"
 
 static unsigned char*
 compress_for_stbiw(unsigned char *data, int data_len, int *out_len, int quality)

src/common/unzip/ioapi.h

@@ -43,7 +43,8 @@
 
 #include <stdio.h>
 #include <stdlib.h>
-#include "zlib.h"
+#include "miniz.h"
+#include "minizconf.h"
 
 #if defined(USE_FILE32API)
 #define fopen64 fopen

src/common/unzip/minizconf.h

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2018 Yamagi Burmeister
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * --------------------------------------------------------------------
+ *
+ * Some additional definitions required by minizip and not provided
+ * by the miniz library.
+ *
+ * --------------------------------------------------------------------
+ */
+
+#ifndef COMMON_UNZIP_MINIZCONF_H
+#define COMMON_UNZIP_MINIZCONF_H
+
+#ifndef OF
+ #define OF(args) args
+#endif
+
+#ifndef ZEXPORT
+ #define ZEXPORT
+#endif
+
+#ifndef z_off_t
+ #define z_off_t long
+#endif
+
+#endif

src/common/unzip/unzip.c

@@ -72,7 +72,8 @@
         #define NOUNCRYPT
 #endif
 
-#include "zlib.h"
+#include "miniz.h"
+#include "minizconf.h"
 #include "unzip.h"
 
 #ifdef STDC

src/common/unzip/unzip.h

@@ -47,9 +47,8 @@
 extern "C" {
 #endif
 
-#ifndef _ZLIB_H
-#include "zlib.h"
-#endif
+#include "miniz.h"
+#include "minizconf.h"
 
 #ifndef  _ZLIBIOAPI_H
 #include "ioapi.h"