Add support for --enable-relocatable in mingw builds on Cygwin hosts.

Reported by Michele Locati <michele@locati.it> in
<https://github.com/mlocati/gettext-iconv-windows/pull/47#issuecomment-3041406917>.

* configure.ac: Invoke gl_BUILD_TO_HOST_BINDIR.
* src/Makefile.in (bindir_c_make, localedir_c_make): New variables.
(iconv_no_i18n.@OBJEXT@, iconv.@OBJEXT@): Fix value of INSTALLDIR and
LOCALEDIR.

ChangeLog

diff --git a/ChangeLog b/ChangeLog
index 359d160..8027934 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2025-07-07  Bruno Haible  <bruno@clisp.org>
+
+	Add support for --enable-relocatable in mingw builds on Cygwin hosts.
+	Reported by Michele Locati <michele@locati.it> in
+	<https://github.com/mlocati/gettext-iconv-windows/pull/47#issuecomment-3041406917>.
+	* configure.ac: Invoke gl_BUILD_TO_HOST_BINDIR.
+	* src/Makefile.in (bindir_c_make, localedir_c_make): New variables.
+	(iconv_no_i18n.@OBJEXT@, iconv.@OBJEXT@): Fix value of INSTALLDIR and
+	LOCALEDIR.
+
 2025-06-09  Bruno Haible  <bruno@clisp.org>
 
 	More install-tests.

configure.ac

diff --git a/configure.ac b/configure.ac
index 63d41db..ca15bd4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -23,6 +23,9 @@
 AC_CONFIG_HEADERS([config.h lib/config.h])
 AC_PROG_MAKE_SET
 
+dnl Define bindir_c and bindir_c_make.
+gl_BUILD_TO_HOST_BINDIR
+
 dnl           checks for basic programs
 
 AC_PROG_CC

src/Makefile.in

diff --git a/src/Makefile.in b/src/Makefile.in
index e8fff47..92307d5 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -56,6 +56,8 @@
 
 # Needed by RELOCATABLE_LDFLAGS.
 host = @host@
+bindir_c_make = @bindir_c_make@
+localedir_c_make = @localedir_c_make@
 
 OBJECTS_RES_yes = iconv.res
 OBJECTS_RES_no =
@@ -78,10 +80,10 @@
 	$(LIBTOOL_LINK) $(CC) $(LDFLAGS) $(CFLAGS) iconv_no_i18n.@OBJEXT@ ../srclib/libicrt.a ../lib/libiconv.la $(OBJECTS_RES_@WOE32@) -o $@
 
 iconv_no_i18n.@OBJEXT@ : $(srcdir)/iconv_no_i18n.c $(srcdir)/iconv.c
-	$(CC) -c $(INCLUDES) -I../lib $(CFLAGS) $(CPPFLAGS) -DINSTALLDIR=\"$(bindir)\" -DLOCALEDIR=\"$(localedir)\" $(srcdir)/iconv_no_i18n.c
+	$(CC) -c $(INCLUDES) -I../lib $(CFLAGS) $(CPPFLAGS) -DINSTALLDIR=$(bindir_c_make) -DLOCALEDIR=$(localedir_c_make) $(srcdir)/iconv_no_i18n.c
 
 iconv.@OBJEXT@ : $(srcdir)/iconv.c
-	$(CC) -c $(INCLUDES) -I../lib $(CFLAGS) $(CPPFLAGS) -DINSTALLDIR=\"$(bindir)\" -DLOCALEDIR=\"$(localedir)\" $(srcdir)/iconv.c
+	$(CC) -c $(INCLUDES) -I../lib $(CFLAGS) $(CPPFLAGS) -DINSTALLDIR=$(bindir_c_make) -DLOCALEDIR=$(localedir_c_make) $(srcdir)/iconv.c
 
 iconv.res : $(srcdir)/../windows/iconv.rc
 	$(WINDRES) `$(SHELL) $(srcdir)/../windows/windres-options --escape $(PACKAGE_VERSION)` -i $(srcdir)/../windows/iconv.rc -o iconv.res --output-format=coff