configure: Make it possible to adjust LDPATH on the configure command line.

[Francois Gouget]

This makes it possible to specify where specific libraries like FreeType can be found at compile time.
---
 configure    | 23 ++++++++++++++++++-----
 configure.ac | 19 ++++++++++++++++---
 2 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/configure b/configure
index a2f8e22..3c23c2d 100755
--- a/configure
+++ b/configure
@@ -633,8 +633,8 @@ LIBPOLL
 LIBDL
 EXTRA_BINARIES
 MAIN_BINARY
-TOOLSEXT
 LDPATH
+TOOLSEXT
 UNWINDFLAGS
 BUILTINFLAG
 EXTRACFLAGS
@@ -13336,20 +13336,33 @@ $as_echo "#define __ASM_STDCALL_FUNC(name,args,code) __ASM_DEFINE_FUNC(name,__AS
 
 
 
-LDPATH=""
-
 case $build_os in
   cygwin*|mingw32*)
     TOOLSEXT=".exe"
 
-    LDPATH="PATH=\"\$(TOOLSDIR)/libs/wine:\$\$PATH\""
+    ;;
+esac
+
+if test -n "$LDPATH"
+then
+    LDPATH="$LDPATH:"
+fi
+case $build_os in
+  cygwin*|mingw32*)
+    LDPATH="PATH=\"\$(TOOLSDIR)/libs/wine:$LDPATH\$\$PATH\""
     ;;
   darwin*|macosx*)
+    if test -n "$LDPATH"
+    then
+        LDPATH="DYLD_LIBRARY_PATH=\"$LDPATH\$\$DYLD_LIBRARY_PATH\""
+    fi
     ;;
   *)
-    LDPATH="LD_LIBRARY_PATH=\"\$(TOOLSDIR)/libs/wine:\$\$LD_LIBRARY_PATH\""
+    LDPATH="LD_LIBRARY_PATH=\"\$(TOOLSDIR)/libs/wine:$LDPATH\$\$LD_LIBRARY_PATH\""
     ;;
 esac
+LDPATH=$LDPATH
+
 
 MAIN_BINARY="wine"
 
diff --git a/configure.ac b/configure.ac
index b687119..2b50724 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1967,18 +1967,31 @@ AC_DEFINE([__ASM_STDCALL_FUNC(name,args,code)],[__ASM_DEFINE_FUNC(name,__ASM_STD
 
 dnl **** Platform-specific checks ****
 
-AC_SUBST(LDPATH,"")
 case $build_os in
   cygwin*|mingw32*)
     AC_SUBST(TOOLSEXT,".exe")
-    LDPATH="PATH=\"\$(TOOLSDIR)/libs/wine:\$\$PATH\""
+    ;;
+esac
+
+if test -n "$LDPATH"
+then
+    LDPATH="$LDPATH:"
+fi
+case $build_os in
+  cygwin*|mingw32*)
+    LDPATH="PATH=\"\$(TOOLSDIR)/libs/wine:$LDPATH\$\$PATH\""
     ;;
   darwin*|macosx*)
+    if test -n "$LDPATH"
+    then
+        LDPATH="DYLD_LIBRARY_PATH=\"$LDPATH\$\$DYLD_LIBRARY_PATH\""
+    fi
     ;;
   *)
-    LDPATH="LD_LIBRARY_PATH=\"\$(TOOLSDIR)/libs/wine:\$\$LD_LIBRARY_PATH\""
+    LDPATH="LD_LIBRARY_PATH=\"\$(TOOLSDIR)/libs/wine:$LDPATH\$\$LD_LIBRARY_PATH\""
     ;;
 esac
+AC_SUBST(LDPATH, $LDPATH)
 
 AC_SUBST(MAIN_BINARY,"wine")
 test "x$enable_win64" != "xyes" || MAIN_BINARY="wine64"
-- 
1.8.4.rc3