Add WITHOUT_JPEG_XL build option

For those who want to force JPEG XL off, and don't use CMake

src/syncterm/GNUmakefile

@@ -39,43 +39,45 @@ else
  CRYPT_LIBS += $(CRYPT_LIB)
 endif
 
-ifdef win
- CFLAGS += -I${3RDP_ROOT}/win32.release/libjxl/include -DJXL_THREADS_STATIC_DEFINE -DJXL_STATIC_DEFINE -DDLLIFY
- LDFLAGS += -L${3RDP_ROOT}/${os}.release/libjxl/lib -static-libstdc++ -static-libgcc
- EXTRA_LIBS += -ljxl
- EXTRA_LIBS += -ljxl_threads
- EXTRA_LIBS += -lbrotlidec
- EXTRA_LIBS += -lbrotlicommon
- EXTRA_LIBS += -lhwy
- EXTRA_LIBS += -mdll
- CFLAGS += -DWITH_JPEG_XL -DWITH_STATIC_JXL
- CFLAGS += -DWITH_JPEG_XL_THREADS
- OBJS += $(MTOBJODIR)$(DIRSEP)libjxl$(OFILE)
- OBJS += $(MTOBJODIR)$(DIRSEP)conn_conpty$(OFILE)
-else
- ifeq ($(shell pkg-config libjxl --exists && echo YES), YES)
-  CFLAGS += $(shell pkg-config libjxl --cflags)
-  EXTRA_LIBS += $(shell pkg-config libjxl --libs)
-  CFLAGS += -DWITH_JPEG_XL
+ifndef WITHOUT_JPEG_XL
+ ifdef win
+  CFLAGS += -I${3RDP_ROOT}/win32.release/libjxl/include -DJXL_THREADS_STATIC_DEFINE -DJXL_STATIC_DEFINE -DDLLIFY
+  LDFLAGS += -L${3RDP_ROOT}/${os}.release/libjxl/lib -static-libstdc++ -static-libgcc
+  EXTRA_LIBS += -ljxl
+  EXTRA_LIBS += -ljxl_threads
+  EXTRA_LIBS += -lbrotlidec
+  EXTRA_LIBS += -lbrotlicommon
+  EXTRA_LIBS += -lhwy
+  EXTRA_LIBS += -mdll
+  CFLAGS += -DWITH_JPEG_XL -DWITH_STATIC_JXL
+  CFLAGS += -DWITH_JPEG_XL_THREADS
   OBJS += $(MTOBJODIR)$(DIRSEP)libjxl$(OFILE)
-  ifeq ($(shell pkg-config libjxl_threads --exists && echo YES), YES)
-   CFLAGS += $(shell pkg-config libjxl_threads --cflags)
-   EXTRA_LIBS += $(shell pkg-config libjxl_threads --libs)
-   CFLAGS += -DWITH_JPEG_XL_THREADS
-  endif
+  OBJS += $(MTOBJODIR)$(DIRSEP)conn_conpty$(OFILE)
  else
-  # TODO: Add x86 libs too!
-  ifeq ($(os),darwin)
-   CFLAGS += -I$(3RDP_ROOT)/$(os).release/libjxl/include -DJXL_THREADS_STATIC_DEFINE -DJXL_STATIC_DEFINE
-   LDFLAGS += -L$(3RDP_ROOT)/$(os).release/libjxl/lib
-   EXTRA_LIBS += -ljxl
-   EXTRA_LIBS += -ljxl_threads
-   EXTRA_LIBS += -lbrotlidec
-   EXTRA_LIBS += -lbrotlicommon
-   EXTRA_LIBS += -lhwy
-   CFLAGS += -DWITH_JPEG_XL -DWITH_STATIC_JXL
-   CFLAGS += -DWITH_JPEG_XL_THREADS
+  ifeq ($(shell pkg-config libjxl --exists && echo YES), YES)
+   CFLAGS += $(shell pkg-config libjxl --cflags)
+   EXTRA_LIBS += $(shell pkg-config libjxl --libs)
+   CFLAGS += -DWITH_JPEG_XL
    OBJS += $(MTOBJODIR)$(DIRSEP)libjxl$(OFILE)
+   ifeq ($(shell pkg-config libjxl_threads --exists && echo YES), YES)
+    CFLAGS += $(shell pkg-config libjxl_threads --cflags)
+    EXTRA_LIBS += $(shell pkg-config libjxl_threads --libs)
+    CFLAGS += -DWITH_JPEG_XL_THREADS
+   endif
+  else
+   # TODO: Add x86 libs too!
+   ifeq ($(os),darwin)
+    CFLAGS += -I$(3RDP_ROOT)/$(os).release/libjxl/include -DJXL_THREADS_STATIC_DEFINE -DJXL_STATIC_DEFINE
+    LDFLAGS += -L$(3RDP_ROOT)/$(os).release/libjxl/lib
+    EXTRA_LIBS += -ljxl
+    EXTRA_LIBS += -ljxl_threads
+    EXTRA_LIBS += -lbrotlidec
+    EXTRA_LIBS += -lbrotlicommon
+    EXTRA_LIBS += -lhwy
+    CFLAGS += -DWITH_JPEG_XL -DWITH_STATIC_JXL
+    CFLAGS += -DWITH_JPEG_XL_THREADS
+    OBJS += $(MTOBJODIR)$(DIRSEP)libjxl$(OFILE)
+   endif
   endif
  endif
 endif