utils/magic_zlib.h: limit #include <zlib.h> to files that need it

Remove limited use HAVE_ZLIB wrapper API into separate header as
utils.h is used in many places and most source files don't need
to drag in the header file from this external dependency.

Copyright date(s) taken from original source file / git blame.

calma/CalmaWrite.c

@@ -44,6 +44,7 @@ static const char rcsid[] __attribute__ ((unused)) ="$Header: /usr/cvsroot/magic
 #include "utils/geometry.h"
 #include "tiles/tile.h"
 #include "utils/utils.h"
+#include "utils/magic_zlib.h"
 #include "utils/hash.h"
 #include "database/database.h"
 #include "database/databaseInt.h"

calma/CalmaWriteZ.c

@@ -54,6 +54,7 @@ static const char rcsid[] __attribute__ ((unused)) ="$Header: /usr/cvsroot/magic
 #include "utils/geometry.h"
 #include "tiles/tile.h"
 #include "utils/utils.h"
+#include "utils/magic_zlib.h"
 #include "utils/hash.h"
 #include "database/database.h"
 #include "database/databaseInt.h"

commands/CmdCD.c

@@ -37,6 +37,7 @@ static const char rcsid[] __attribute__ ((unused)) = "$Header: /usr/cvsroot/magi
 #include "utils/main.h"
 #include "commands/commands.h"
 #include "utils/utils.h"
+#include "utils/magic_zlib.h"
 #include "textio/textio.h"
 #include "drc/drc.h"
 #include "graphics/graphics.h"

database/DBio.c

@@ -60,6 +60,7 @@ static char rcsid[] __attribute__ ((unused)) = "$Header: /usr/cvsroot/magic-8.0/
 #include "utils/geometry.h"
 #include "tiles/tile.h"
 #include "utils/utils.h"
+#include "utils/magic_zlib.h"
 #include "utils/hash.h"
 #include "database/database.h"
 #include "database/databaseInt.h"

utils/flock.c

@@ -23,6 +23,7 @@
 #include "database/database.h"
 #include "windows/windows.h"
 #include "utils/malloc.h"
+#include "utils/magic_zlib.h"
 
 /* C99 compat */
 #include "textio/textio.h"

utils/magic_zlib.h

@@ -0,0 +1,39 @@
+/* zlib.h --
+ *
+ * Routines relating to the external dependency zlib
+ *
+ *     *********************************************************************
+ *     * Copyright (C) 2022, 2024 Regents of the University of California. *
+ *     * Permission to use, copy, modify, and distribute this              *
+ *     * software and its documentation for any purpose and without        *
+ *     * fee is hereby granted, provided that the above copyright          *
+ *     * notice appear in all copies.  The University of California        *
+ *     * makes no representations about the suitability of this            *
+ *     * software for any purpose.  It is provided "as is" without         *
+ *     * express or implied warranty.  Export of this software outside     *
+ *     * of the United States of America may require an export license.    *
+ *     *********************************************************************
+ *
+ * rcsid="$Header"
+ */
+
+#ifndef _MAGIC__UTILS__MAGIC_ZLIB_H
+#define _MAGIC__UTILS__MAGIC_ZLIB_H
+
+#ifdef HAVE_ZLIB
+
+#include <zlib.h>
+
+extern gzFile PaZOpen(const char *file, const char *mode, const char *ext, const char *path, const char *library,
+                      char **pRealName);
+extern gzFile PaLockZOpen(const char *file, const char *mode, const char *ext, const char *path, const char *library,
+                          char **pRealName, bool *is_locked, int *fdp);
+extern char *PaCheckCompressed(const char *filename);
+
+#ifdef FILE_LOCKS
+extern gzFile flock_zopen();
+#endif
+
+#endif
+
+#endif /* _MAGIC__UTILS__MAGIC_ZLIB_H */

utils/path.c

@@ -40,6 +40,7 @@ static char rcsid[] __attribute__ ((unused)) = "$Header: /usr/cvsroot/magic-8.0/
 #include "utils/hash.h"
 #include "utils/malloc.h"
 #include "utils/utils.h"
+#include "utils/magic_zlib.h"
 
 /* Library routines: */
 

utils/utils.h

@@ -21,12 +21,8 @@
 #ifndef _UTILS_H
 #define _UTILS_H 1
 
-#ifdef HAVE_ZLIB
-#include <zlib.h>
-#endif
-
-#include "utils/tech.h"
 #include "utils/magic.h"
+#include "utils/tech.h"
 
 /*
  * Cast second argument to LookupStruct() to (LookupTable *) to
@@ -76,21 +72,10 @@ extern void SetNoisyInt(int *parm, const char *valueS, FILE *file);
 extern void SetNoisyDI(dlong *parm, const char *valueS, FILE *file);
 extern bool ParsSplit();
 
-#ifdef HAVE_ZLIB
-extern gzFile PaZOpen(const char *file, const char *mode, const char *ext, const char *path, const char *library,
-                      char **pRealName);
-extern gzFile PaLockZOpen(const char *file, const char *mode, const char *ext, const char *path, const char *library,
-                          char **pRealName, bool *is_locked, int *fdp);
-extern char *PaCheckCompressed(const char *filename);
-#endif
-
 extern int SetNoisyBool(bool *parm, const char *valueS, FILE *file);
 
 #ifdef FILE_LOCKS
 extern FILE *flock_open();
-#ifdef HAVE_ZLIB
-extern gzFile flock_zopen();
-#endif
 #endif
 
 /* The following macro takes an integer and returns another integer that