Rebase of 014_hplip-3.25.2-missing-includes-and-definitions.patch from
hplip-3.26.4-patches-1.tar.xz. Carried whole because eapply is all-or-nothing:
one of its twelve hunks stopped applying to 3.26.6, so the patch has to be
dropped from the fetched patchset and reinstated from here. See
hplip-makefile-am-patchset-rebase.patch for the wider story.

Two of the original hunks are deliberately NOT reproduced, because 3.26.6
adopted them upstream:

  protocol/hp_ipp.c   now opens with #define _GNU_SOURCE of its own.
  scan/sane/sclpml.c  now includes <sys/time.h> (and <ctype.h>) directly.

The sclpml.c _GNU_SOURCE define IS still reproduced and is still load-bearing:
sclpml.c calls strcasestr() at line 1914, which glibc only declares under
_GNU_SOURCE.

The rest is unchanged in intent -- missing includes (<stdlib.h>, <unistd.h>),
the Python 3 shims in pcardext.c, and the five prototypes in protocol/hp_ipp.h
that prnt/cupsext/cupsext.c calls. Those prototypes are what actually breaks the
build when this patch is missing: cupsext.c fails with "implicit declaration of
function 'addCupsPrinter'" and four more of the same, which under -Werror=
implicit-function-declaration is fatal.

--- a/common/utils.c
+++ b/common/utils.c
@@ -1,3 +1,7 @@
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
 #include "utils.h"
 #include "string.h"
 #include <dlfcn.h>
--- a/io/hpmud/jd.c
+++ b/io/hpmud/jd.c
@@ -31,6 +31,7 @@
 #endif
 
 #include <signal.h>
+#include <stdlib.h>
 #include "hpmud.h"
 #include "hpmudi.h"
 
--- a/pcard/pcardext/pcardext.c
+++ b/pcard/pcardext/pcardext.c
@@ -39,6 +39,12 @@
 #define PY_SSIZE_T_MIN INT_MIN
 #endif
 
+#if PY_MAJOR_VERSION >= 3
+#define PyString_AsStringAndSize PyBytes_AsStringAndSize
+#define PyString_FromStringAndSize PyBytes_FromStringAndSize
+#define PyInt_AS_LONG PyLong_AS_LONG
+#endif
+
 int verbose=0;
 
 PyObject * readsectorFunc = NULL;
@@ -81,8 +87,11 @@
     
     if( writesectorFunc )
     {
+#if PY_MAJOR_VERSION >= 3
         result = PyObject_CallFunction( writesectorFunc, "iis#", sector, nsector, buf, size );
-        
+#else
+        result = PyObject_CallFunction( writesectorFunc, "iiy#", sector, nsector, buf, size );
+#endif
         return PyInt_AS_LONG( result );
     }
 
@@ -236,6 +245,29 @@
 
 static char pcardext_documentation[] = "Python extension for HP photocard services";
 
+#if PY_MAJOR_VERSION >= 3
+static struct PyModuleDef moduledef = {
+        .m_base = PyModuleDef_HEAD_INIT,
+        .m_name = "pcardext",
+        .m_doc = pcardext_documentation,
+        .m_size = -1,
+        .m_methods = pcardext_methods,
+        .m_slots = NULL,
+        .m_traverse = NULL,
+        .m_clear = NULL,
+        .m_free = NULL,
+};
+
+PyMODINIT_FUNC
+PyInit_pcardext( void )
+{
+       PyObject *module = PyModule_Create2(&moduledef, PYTHON_API_VERSION);
+
+       return module;
+}
+
+#else
+
 void initpcardext( void )
 {
     PyObject * mod = Py_InitModule4( "pcardext", pcardext_methods, 
@@ -246,4 +278,4 @@
       return;
 }
 
-
+#endif
--- a/protocol/hp_ipp.h
+++ b/protocol/hp_ipp.h
@@ -149,6 +149,7 @@
 
 
 http_t*    acquireCupsInstance();
+void _releaseCupsInstance();
 const char *getCupsErrorString(int status);
 void freePrinterList(printer_t *list);
  
@@ -163,6 +164,11 @@
 ipp_t * networkDoRequest(ipp_t *request, char* device_uri,const char *resource);
 ipp_t * getDeviceStatusAttributes(char* device_uri,char* printer_name, int *count);
 int     getCupsPrinters(printer_t **printer_list);
+int addCupsPrinter(char *name, char *device_uri, char *location, char *ppd_file,
+                  char *model, char *info);
+int delCupsPrinter(char *pr_name);
+int setDefaultCupsPrinter(char *pr_name);
+int controlCupsPrinter(char *pr_name, int op);
 
 HPIPP_RESULT parseResponseHeader(char* header, int *content_length, int *chunked, int* header_size);
 HPIPP_RESULT prepend_http_header(raw_ipp *raw_request,const char *resource);
--- a/scan/sane/bb_ledm.c
+++ b/scan/sane/bb_ledm.c
@@ -27,6 +27,7 @@
 # include "xml.h"
 # include <stdlib.h>
 
+# include <unistd.h>
 # include <stdint.h>
 
 # define _STRINGIZE(x) #x
--- a/scan/sane/http.c
+++ b/scan/sane/http.c
@@ -33,6 +33,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <string.h>
 #include <syslog.h>
 #include <ctype.h>
--- a/scan/sane/sclpml.c
+++ b/scan/sane/sclpml.c
@@ -25,6 +25,10 @@
 
 \************************************************************************************/
 
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>