use libmagic to detect valid file formats

Writing our own magic bytes detection is prone to errors and an
everlasting catch-up-game. Let's use libmagic to get things right,
this is less code and makes things more reliable.

Building without libmagic is still possible. That will make the code
act like specifying FEH_SKIP_MAGIC=1, effectively passing everything
to imlib2.

1 files changed, 6 insertions, 0 deletions

diff --git a/config.mk b/config.mk
index 2d63f72..910eac7 100644
--- a/config.mk
+++ b/config.mk
@@ -6,6 +6,7 @@ curl ?= 1
 debug ?= 0
 exif ?= 0
 help ?= 0
+magic ?= 1
 mkstemps ?= 1
 verscmp ?= 1
 xinerama ?= 1
@@ -68,6 +69,11 @@ ifeq (${mkstemps},1)
 	CFLAGS += -DHAVE_MKSTEMPS
 endif
 
+ifeq (${magic},1)
+	CFLAGS += -DHAVE_LIBMAGIC
+	LDLIBS += -lmagic
+endif
+
 ifeq (${verscmp},1)
 	CFLAGS += -DHAVE_STRVERSCMP
 endif