From: Andrew Udvare <audvare@gmail.com>
Subject: [PATCH] build: respect CFLAGS/LDFLAGS and install the libquasselc.so symlink

Two build-system problems:

* CFLAGS was assigned with := , discarding any flags the caller set, and the
  link rule never passed LDFLAGS at all.
* quasselc.pc advertises "Libs: -L${libdir} -lquasselc", but install only ever
  put libquasselc.so.0 in place. Without the unversioned symlink, -lquasselc
  cannot be resolved, so every consumer of the .pc file fails to link.

Upstream: https://github.com/phhusson/QuasselC (no activity since 2017-01)

diff --git a/Makefile b/Makefile
index 88f8845..536ea15 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,8 @@ prefix ?= /usr/local
 libdir ?= $(prefix)/lib
 includedir ?= $(prefix)/include
 
-CFLAGS:=-Wall -g -Wextra $(shell pkg-config glib-2.0 --cflags) -Wswitch-enum -std=gnu11 -O2 -fPIC
+CFLAGS ?= -g -O2
+CFLAGS += -Wall -Wextra $(shell pkg-config glib-2.0 --cflags) -Wswitch-enum -std=gnu11 -fPIC
 SO_VERSION = 0
 VERSION = 0
 INSTALL = install
@@ -15,7 +16,7 @@ lib_objects=setters.o getters.o main.o cmds.o negotiation.o io.o symbols.o
 all: bot libquasselc.so.$(VERSION) quasselc.pc
 
 libquasselc.so.$(VERSION): $(lib_objects)
-	$(CC) -shared -o $@ -Wl,-soname,libquasselc.so.$(SO_VERSION) $^ $(LDLIBS)
+	$(CC) -shared $(CFLAGS) $(LDFLAGS) -o $@ -Wl,-soname,libquasselc.so.$(SO_VERSION) $^ $(LDLIBS)
 
 bot: bot.o display.o libquasselc.so.$(VERSION)
 	$(CC) -o $@ $^ $(LDLIBS) $(BOTLIBS)
@@ -32,6 +33,7 @@ quasselc.pc: quasselc.pc.in
 install: libquasselc.so.$(VERSION) quasselc.pc
 	$(INSTALL) -d $(DESTDIR)$(libdir)
 	$(INSTALL) libquasselc.so.$(VERSION) $(DESTDIR)$(libdir)
+	ln -sf libquasselc.so.$(VERSION) $(DESTDIR)$(libdir)/libquasselc.so
 	$(INSTALL) -d $(DESTDIR)$(libdir)/pkgconfig
 	$(INSTALL) -m 0644 quasselc.pc $(DESTDIR)$(libdir)/pkgconfig
 	$(INSTALL) -d $(DESTDIR)$(includedir)/quasselc