port: display branch name in legal screen

Makefile.port

@@ -116,14 +116,23 @@ else
 endif
 
 VERSION_HASH := $(shell git rev-parse --short HEAD)
+VERSION_BRANCH := $(shell git rev-parse --abbrev-ref HEAD)
 VERSION_TARGET := $(TARGET_PLATFORM)
 VERSION_ROMID := $(ROMID)
 
+ifeq ($(VERSION_BRANCH),)
+  VERSION_BRANCH := port-custom
+endif
+ifeq ($(VERSION_BRANCH),HEAD)
+  VERSION_BRANCH := port-custom
+endif
+
 DEFINES := \
   VERSION=$(VERSION) \
   VERSION_HASH=\"$(VERSION_HASH)\" \
   VERSION_TARGET=\"$(VERSION_TARGET)\" \
   VERSION_ROMID=\"$(VERSION_ROMID)\" \
+  VERSION_BRANCH=\"$(VERSION_BRANCH)\" \
   MATCHING=0 \
   PAL=$(IS_PAL) \
   PIRACYCHECKS=0 \

src/game/title.c

@@ -372,6 +372,8 @@ Gfx *titleRenderLegal(Gfx *gdl)
 					elem->textptr = VERSION_HASH " (" VERSION_TARGET ")";
 				} else if (elem->textid == L_OPTIONS_083) {
 					elem->textptr = VERSION_ROMID;
+				} else if (elem->textid == L_OPTIONS_082) {
+					elem->textptr = "Perfect Dark (" VERSION_BRANCH ")";
 				}
 #endif
 				break;