Fix for Ubuntu Xenial irssi-plugin-otr package

otr_preload.c

/*
 * The package irssi-plugin-otr provides a library file (libotr.so) which is
 * incorrectly compiled on Ubuntu 16.04. There's an open issue
 * (https://bugs.launchpad.net/ubuntu/+source/irssi-plugin-otr/+bug/1579548).
 *
 * This is a dirty workaround.
 * Usage: LD_PRELOAD=$(pwd)/otr_preload.so irssi
 *
 * Makefile:

CFLAGS := -W -Wall -Wextra
LDFLAGS := -ldl
TARGET := otr_preload.so

ifeq ($(ARM),1)
    CC := /usr/bin/arm-linux-gnueabihf-gcc
    CFLAGS += -I/usr/arm-linux-gnueabihf/include
endif

all: $(TARGET)

%.so: %.o
	$(CC) -shared $^ -o $@ $(LDFLAGS)

%.o: %.c
	$(CC) $(CFLAGS) -fPIC -o $@ -c $^

clean:
	rm -f $(TARGET) *.o

 */

#define _GNU_SOURCE
#include <dlfcn.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdbool.h>

#define IRSSI_ABI_VERSION	2

/* don't require glib header files */
#define gboolean	bool
#define gchar		char
#define gpointer	unsigned long
#define GModule		void

static gboolean (*orig_g_module_symbol)(GModule *, const gchar *, gpointer *);

void otr_abicheck(int *version)
{
	*version = IRSSI_ABI_VERSION;
}

gboolean g_module_symbol(GModule *module, const gchar *symbol_name, gpointer *symbol)
{
	if (strcmp(symbol_name, "otr_abicheck") == 0) {
		*symbol = (gpointer)otr_abicheck;
		return true;
	} else {
		return orig_g_module_symbol(module, symbol_name, symbol);
	}
}

static int __attribute__ ((constructor)) initfunc(void)
{
	orig_g_module_symbol = dlsym(RTLD_NEXT, "g_module_symbol");
	if (orig_g_module_symbol == NULL) {
		fprintf(stderr, "can't find g_module_symbol\n");
		sleep(1);
	}

	return 0;
}