diff -up texinfo-6.4/install-info/install-info.c.orig texinfo-6.4/install-info/install-info.c

--- texinfo-6.4/install-info/install-info.c.orig	2016-03-04 18:52:26.000000000 +0100

+++ texinfo-6.4/install-info/install-info.c	2017-06-27 15:14:20.167998983 +0200

@@ -22,6 +22,7 @@

 #include <getopt.h>

 #include <regex.h>

 #include <argz.h>

+#include <zlib.h>

 #define TAB_WIDTH 8

@@ -684,15 +685,15 @@ The first time you invoke Info you start

    Return either stdin reading the file, or a non-stdin pipe reading

    the output of the compression program.  */

-FILE *

+void *

 open_possibly_compressed_file (char *filename,

     void (*create_callback) (char *),

-    char **opened_filename, char **compression_program) 

+    char **opened_filename, char **compression_program, int *is_pipe)

 {

   char *local_opened_filename, *local_compression_program;

   int nread;

   char data[13];

-  FILE *f;

+  gzFile *f;

   /* We let them pass NULL if they don't want this info, but it's easier

      to always determine it.  */

@@ -700,48 +701,48 @@ open_possibly_compressed_file (char *fil

     opened_filename = &local_opened_filename;

   *opened_filename = filename;

-  f = fopen (*opened_filename, FOPEN_RBIN);

+  f = gzopen (*opened_filename, FOPEN_RBIN);

   if (!f)

     {

       *opened_filename = concat (filename, ".gz", "");

-      f = fopen (*opened_filename, FOPEN_RBIN);

+      f = gzopen (*opened_filename, FOPEN_RBIN);

     }

   if (!f)

     {

       free (*opened_filename);

       *opened_filename = concat (filename, ".xz", "");

-      f = fopen (*opened_filename, FOPEN_RBIN);

+      f = gzopen (*opened_filename, FOPEN_RBIN);

     }

   if (!f)

     {

       free (*opened_filename);

       *opened_filename = concat (filename, ".bz2", "");

-      f = fopen (*opened_filename, FOPEN_RBIN);

+      f = gzopen (*opened_filename, FOPEN_RBIN);

     }

   if (!f)

     {

       free (*opened_filename);

       *opened_filename = concat (filename, ".lz", "");

-      f = fopen (*opened_filename, FOPEN_RBIN);

+      f = gzopen (*opened_filename, FOPEN_RBIN);

     }

   if (!f)

     {

      free (*opened_filename);

      *opened_filename = concat (filename, ".lzma", "");

-     f = fopen (*opened_filename, FOPEN_RBIN);

+     f = gzopen (*opened_filename, FOPEN_RBIN);

     }

 #ifdef __MSDOS__

   if (!f)

     {

       free (*opened_filename);

       *opened_filename = concat (filename, ".igz", "");

-      f = fopen (*opened_filename, FOPEN_RBIN);

+      f = gzopen (*opened_filename, FOPEN_RBIN);

     }

   if (!f)

     {

       free (*opened_filename);

       *opened_filename = concat (filename, ".inz", "");

-      f = fopen (*opened_filename, FOPEN_RBIN);

+      f = gzopen (*opened_filename, FOPEN_RBIN);

     }

 #endif /* __MSDOS__ */

   if (!f)

@@ -757,7 +758,7 @@ open_possibly_compressed_file (char *fil

           (*create_callback) (filename);

           /* And try opening it again.  */

-          f = fopen (*opened_filename, FOPEN_RBIN);

+          f = gzopen (*opened_filename, FOPEN_RBIN);

           if (!f)

             return 0;

         }

@@ -767,26 +768,26 @@ open_possibly_compressed_file (char *fil

   /* Read first few bytes of file rather than relying on the filename.

      If the file is shorter than this it can't be usable anyway.  */

-  nread = fread (data, sizeof (data), 1, f);

-  if (nread != 1)

+  nread = gzread (f, data, sizeof (data));

+  if (nread != sizeof (data))

     {

-      if (nread == 0)

+      if (nread >= 0)

         {

           /* Try to create the file if its empty. */

-          if (feof (f) && create_callback)

+          if (gzeof (f) && create_callback)

             {

-              if (fclose (f) != 0)

+              if (gzclose (f) < 0)

                 return 0; /* unknown error closing file */

               if (remove (filename) != 0)

                 return 0; /* unknown error deleting file */

               (*create_callback) (filename);

-              f = fopen (*opened_filename, FOPEN_RBIN);

+              f = gzopen (*opened_filename, FOPEN_RBIN);

               if (!f)

                 return 0;

-              nread = fread (data, sizeof (data), 1, f);

-              if (nread == 0)

+              nread = gzread (f, data, sizeof (data));

+              if (nread <= 0)

                 return 0;

               goto determine_file_type; /* success */

             }

@@ -857,35 +858,40 @@ determine_file_type:

     *compression_program = NULL;

   /* Seek back over the magic bytes.  */

-  if (fseek (f, 0, 0) < 0)

+  if (gzseek (f, 0, SEEK_SET) == -1)

     return 0;

   if (*compression_program)

     { /* It's compressed, so open a pipe.  */

+      FILE *p;

       char *command = concat (*compression_program, " -d", "");

-      if (fclose (f) < 0)

+      if (gzclose (f) < 0)

         return 0;

-      f = freopen (*opened_filename, FOPEN_RBIN, stdin);

-      if (!f)

+      p = freopen (*opened_filename, FOPEN_RBIN, stdin);

+      if (!p)

         return 0;

-      f = popen (command, "r");

-      if (!f)

+      p = popen (command, "r");

+      if (!p)

         {

           /* Used for error message in calling code. */

           *opened_filename = command;

           return 0;

         }

+      else

+        *is_pipe = 1;

+      return p;

     }

   else

     {

-#if O_BINARY

+#if 0 && O_BINARY

       /* Since this is a text file, and we opened it in binary mode,

          switch back to text mode.  */

       f = freopen (*opened_filename, "r", f);

       if (! f)

 	return 0;

 #endif

+      *is_pipe = 0;

     }

   return f;

@@ -904,7 +910,8 @@ readfile (char *filename, int *sizep,

     void (*create_callback) (char *), char **opened_filename,

     char **compression_program)

 {

-  FILE *f;

+  void *f;

+  int pipe_p;

   int filled = 0;

   int data_size = 8192;

   char *data = xmalloc (data_size);

@@ -912,14 +919,20 @@ readfile (char *filename, int *sizep,

   /* If they passed the space for the file name to return, use it.  */

   f = open_possibly_compressed_file (filename, create_callback,

                                      opened_filename,

-                                     compression_program);

+                                     compression_program,

+                                     &pipe_p);

   if (!f)

     return 0;

   for (;;)

     {

-      int nread = fread (data + filled, 1, data_size - filled, f);

+      int nread;

+

+      if (pipe_p)

+        nread = fread (data + filled, 1, data_size - filled, f);

+      else

+        nread = gzread (f, data + filled, data_size - filled);

       if (nread < 0)

         return 0;

       if (nread == 0)

@@ -938,8 +951,10 @@ readfile (char *filename, int *sizep,

   /* We need to close the stream, since on some systems the pipe created

      by popen is simulated by a temporary file which only gets removed

      inside pclose.  */

-  if (f != stdin)

+  if (pipe_p)

     pclose (f);

+  else

+    gzclose (f);

   *sizep = filled;

   return data;

diff -up texinfo-6.4/install-info/Makefile.in.orig texinfo-6.4/install-info/Makefile.in

--- texinfo-6.4/install-info/Makefile.in.orig	2017-06-23 08:04:39.000000000 +0200

+++ texinfo-6.4/install-info/Makefile.in	2017-06-27 15:14:20.167998983 +0200

@@ -221,7 +221,7 @@ am__installdirs = "$(DESTDIR)$(bindir)"

 PROGRAMS = $(bin_PROGRAMS)

 am_ginstall_info_OBJECTS = install-info.$(OBJEXT)

 ginstall_info_OBJECTS = $(am_ginstall_info_OBJECTS)

-ginstall_info_LDADD = $(LDADD)

+ginstall_info_LDADD = $(LDADD) -lz

 am__DEPENDENCIES_1 =

 ginstall_info_DEPENDENCIES = $(top_builddir)/gnulib/lib/libgnu.a \

 	$(am__DEPENDENCIES_1)