Allow the built-in exec path to be relative to the command invocation path

If GIT_EXEC_PATH (the macro that is defined in the Makefile) is relative,
it is interpreted relative to the command's invocation path, which usually
is $(bindir).

The Makefile rules were written with the assumption that $(gitexecdir) is
an absolute path. We introduce a separate variable that names the
(absolute) installation directory.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -170,6 +170,16 @@ ALL_CFLAGS = $(CFLAGS)
 ALL_LDFLAGS = $(LDFLAGS)
 STRIP ?= strip
 
+# Among the variables below, these:
+#   gitexecdir
+#   template_dir
+#   htmldir
+#   ETC_GITCONFIG (but not sysconfdir)
+# can be specified as a relative path ../some/where/else (which must begin
+# with ../); this is interpreted as relative to $(bindir) and "git" at
+# runtime figures out where they are based on the path to the executable.
+# This can help installing the suite in a relocatable way.
+
 prefix = $(HOME)
 bindir = $(prefix)/bin
 mandir = $(prefix)/share/man
@@ -205,7 +215,7 @@ GITWEB_FAVICON = git-favicon.png
 GITWEB_SITE_HEADER =
 GITWEB_SITE_FOOTER =
 
-export prefix bindir gitexecdir sharedir htmldir sysconfdir
+export prefix bindir sharedir htmldir sysconfdir
 
 CC = gcc
 AR = ar
@@ -1321,22 +1331,30 @@ template_instdir = $(template_dir)
 endif
 export template_instdir
 
+ifeq ($(firstword $(subst /, ,$(gitexecdir))),..)
+gitexec_instdir = $(bindir)/$(gitexecdir)
+else
+gitexec_instdir = $(gitexecdir)
+endif
+gitexec_instdir_SQ = $(subst ','\'',$(gitexec_instdir))
+export gitexec_instdir
+
 install: all
 	$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(bindir_SQ)'
-	$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(gitexecdir_SQ)'
-	$(INSTALL) $(ALL_PROGRAMS) '$(DESTDIR_SQ)$(gitexecdir_SQ)'
+	$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(gitexec_instdir_SQ)'
+	$(INSTALL) $(ALL_PROGRAMS) '$(DESTDIR_SQ)$(gitexec_instdir_SQ)'
 	$(INSTALL) git$X git-upload-pack$X git-receive-pack$X git-upload-archive$X '$(DESTDIR_SQ)$(bindir_SQ)'
 	$(MAKE) -C templates DESTDIR='$(DESTDIR_SQ)' install
 	$(MAKE) -C perl prefix='$(prefix_SQ)' DESTDIR='$(DESTDIR_SQ)' install
 ifndef NO_TCLTK
 	$(MAKE) -C gitk-git install
-	$(MAKE) -C git-gui install
+	$(MAKE) -C git-gui gitexecdir='$(gitexec_instdir_SQ)' install
 endif
 ifneq (,$X)
-	$(foreach p,$(patsubst %$X,%,$(filter %$X,$(ALL_PROGRAMS) $(BUILT_INS) git$X)), $(RM) '$(DESTDIR_SQ)$(gitexecdir_SQ)/$p';)
+	$(foreach p,$(patsubst %$X,%,$(filter %$X,$(ALL_PROGRAMS) $(BUILT_INS) git$X)), $(RM) '$(DESTDIR_SQ)$(gitexec_instdir_SQ)/$p';)
 endif
 	bindir=$$(cd '$(DESTDIR_SQ)$(bindir_SQ)' && pwd) && \
-	execdir=$$(cd '$(DESTDIR_SQ)$(gitexecdir_SQ)' && pwd) && \
+	execdir=$$(cd '$(DESTDIR_SQ)$(gitexec_instdir_SQ)' && pwd) && \
 	if test "z$$bindir" != "z$$execdir"; \
 	then \
 		ln -f "$$bindir/git$X" "$$execdir/git$X" || \

exec_cmd.c

@@ -7,40 +7,6 @@ extern char **environ;
 static const char *argv_exec_path;
 static const char *argv0_path;
 
-static const char *builtin_exec_path(void)
-{
-#ifndef __MINGW32__
-	return GIT_EXEC_PATH;
-#else
-	int len;
-	char *p, *q, *sl;
-	static char *ep;
-	if (ep)
-		return ep;
-
-	len = strlen(_pgmptr);
-	if (len < 2)
-		return ep = ".";
-
-	p = ep = xmalloc(len+1);
-	q = _pgmptr;
-	sl = NULL;
-	/* copy program name, turn '\\' into '/', skip last part */
-	while ((*p = *q)) {
-		if (*q == '\\' || *q == '/') {
-			*p = '/';
-			sl = p;
-		}
-		p++, q++;
-	}
-	if (sl)
-		*sl = '\0';
-	else
-		ep[0] = '.', ep[1] = '\0';
-	return ep;
-#endif
-}
-
 const char *system_path(const char *path)
 {
 	if (!is_absolute_path(path) && argv0_path) {
@@ -75,7 +41,7 @@ const char *git_exec_path(void)
 		return env;
 	}
 
-	return builtin_exec_path();
+	return system_path(GIT_EXEC_PATH);
 }
 
 static void add_path(struct strbuf *out, const char *path)
@@ -99,7 +65,7 @@ void setup_path(void)
 
 	add_path(&new_path, argv_exec_path);
 	add_path(&new_path, getenv(EXEC_PATH_ENVIRONMENT));
-	add_path(&new_path, builtin_exec_path());
+	add_path(&new_path, system_path(GIT_EXEC_PATH));
 	add_path(&new_path, argv0_path);
 
 	if (old_path)