libzdb: fix uclibc build issue

libmariadb 10.2 needs to be linked in together with iconv. On musl and
glibc iconv is part of libc. That's not the case for uclibc, where
libiconv-full needs to be used. This commit adds -liconv to the linker
flags and aids libzdb in finding libiconv.

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>

libs/libzdb/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=libzdb
 PKG_VERSION:=3.1
-PKG_RELEASE:=4
+PKG_RELEASE:=5
 PKG_LICENSE:=GPL-3.0
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
@@ -23,6 +23,14 @@ PKG_BUILD_DEPENDS:=libzdb/host
 
 include $(INCLUDE_DIR)/package.mk
 
+# Help libzdb find libiconv.so when using uClibc.
+ifneq ($(CONFIG_USE_UCLIBC),)
+TARGET_CPPFLAGS+= \
+	-I$(STAGING_DIR)/usr/lib/libiconv-full/include
+TARGET_LDFLAGS += \
+	-L$(STAGING_DIR)/usr/lib/libiconv-full/lib
+endif
+
 define Package/libzdb
     SECTION:=libs
     CATEGORY:=Libraries

libs/libzdb/patches/010-cross-compile-fixes.patch

@@ -40,7 +40,7 @@ diff -rupN libzdb-3.1.orig/configure.ac libzdb-3.1/configure.ac
 -                DBCPPFLAGS="$DBCPPFLAGS `$MYSQLCONFIG --include`"
 -                DBLDFLAGS="$DBLDFLAGS `$MYSQLCONFIG --libs`"
 +                DBCPPFLAGS="$DBCPPFLAGS -I$STAGING_DIR/usr/include/mysql"
-+                DBLDFLAGS="$DBLDFLAGS -L$STAGING_DIR/usr/lib/mysql -L$STAGING_DIR/usr/lib -lmysqlclient -lz -lcrypt -lm"
++                DBLDFLAGS="$DBLDFLAGS -L$STAGING_DIR/usr/lib/mysql -L$STAGING_DIR/usr/lib -lmysqlclient -liconv -lz -lcrypt -lm"
                  AC_DEFINE([HAVE_LIBMYSQLCLIENT], 1, [Define to 1 to enable mysql])
          else
                  CPPFLAGS=$svd_CPPFLAGS