Fixed conditions with variable BRANCH

conf.d/mixin.mk

 ### various mixins with their origin
 
 # for stable branch base kits
-ifdef BRANCH
+ifneq (,$(BRANCH))
 STARTERKIT := mixin/starterkit
 mixin/starterkit: use/browser/firefox/esr
 	@$(call set,BRANDING,alt-starterkit)

conf.d/regular.mk

@@ -8,7 +8,7 @@ distro/.regular-bare: distro/.base use/kernel/net use/docs/license \
 	use/stage2/rtc use/stage2/sbc use/stage2/scsi use/stage2/usb \
 	$(STARTERKIT)
 	@$(call try,SAVE_PROFILE,yes)
-ifndef BRANCH
+ifeq (,$(BRANCH))
 ifeq (,$(filter-out i586 x86_64,$(ARCH)))
 	@$(call set,BOOTLOADER,grubpcboot)
 endif
@@ -138,7 +138,7 @@ distro/regular-gnustep-systemd: distro/.regular-wm +systemd \
 	mixin/regular-wmaker mixin/regular-gnustep; @:
 
 distro/regular-xfce: distro/.regular-gtk mixin/regular-xfce; @:
-ifndef BRANCH
+ifeq (,$(BRANCH))
 ifeq (,$(filter-out i586 x86_64,$(ARCH)))
 	@$(call set,KFLAVOURS,std-def un-def)
 endif

doc/profiles.mk.sample

@@ -2,7 +2,7 @@
 # NB: REPORT doesn't work here, it's somewhat special
 
 # where to look for apt.conf; system one used by default
-ifdef BRANCH
+ifneq (,$(BRANCH))
 APTCONF = ~/apt/apt.conf.$(BRANCH).$(ARCH)
 else
 APTCONF = ~/apt/apt.conf.sisyphus.$(ARCH)

main.mk

@@ -17,7 +17,7 @@ endif
 IMAGE_CONF    := $(firstword $(subst ., ,$(IMAGE_TARGET)))# ve/generic
 IMAGE_CLASS   := $(firstword $(subst /, ,$(IMAGE_TARGET)))# ve
 IMAGE_FILE    := $(lastword  $(subst /, ,$(IMAGE_TARGET)))# generic.tar.gz
-ifdef BRANCH
+ifneq (,$(BRANCH))
 IMAGE_FILE    := $(subst regular,alt-$(BRANCH),$(IMAGE_FILE))
 endif
 IMAGE_NAME    := $(firstword $(subst ., ,$(IMAGE_FILE)))#   generic