3 files changed, 19 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index 733fb8d1acb..88ddf0022a5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-05-17  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * Makefile.in (src): Provide the name of the VCS file that witnesses
+        a pull.
+        ($(srcdir)/src/config.in): Handle accidental removal of src/config.in.
+
 2010-05-17  Glenn Morris  <rgm@gnu.org>
 
         * configure.in (OLDXMENU_DEPS): New output variable.
diff --git a/Makefile.in b/Makefile.in
index 775c591af26..cd677d3295d 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -335,9 +335,13 @@ src: Makefile FRC
               CC='${CC}' CFLAGS='${CFLAGS}' CPPFLAGS='${CPPFLAGS}'         \
               LDFLAGS='${LDFLAGS}' MAKE='${MAKE}' BOOTSTRAPEMACS="$$boot"; \
         fi;
+        if [ -r .bzr/checkout/dirstate ]; then                  \
+            vcswitness="$$(pwd)/.bzr/checkout/dirstate";        \
+        fi;                                                     \
         cd $@; $(MAKE) all $(MFLAGS)                           \
           CC='${CC}' CFLAGS='${CFLAGS}' CPPFLAGS='${CPPFLAGS}' \
-          LDFLAGS='${LDFLAGS}' MAKE='${MAKE}' BOOTSTRAPEMACS=""
+          LDFLAGS='${LDFLAGS}' MAKE='${MAKE}' BOOTSTRAPEMACS="" \
+          VCSWITNESS="$$vcswitness"
 
 blessmail: Makefile src FRC
         cd lib-src; $(MAKE) maybe-blessmail $(MFLAGS) \
@@ -369,7 +373,11 @@ $(srcdir)/configure: $(AUTOCONF_INPUTS)
         cd ${srcdir} && autoconf
 
 $(srcdir)/src/config.in: $(srcdir)/src/stamp-h.in
-        @true
+        @ # Usually, there's no need to rebuild src/config.in just
+        @ # because stamp-h.in has changed (since building stamp-h.in
+        @ # refreshes config.in as well), but if config.in is missing
+        @ # then we really need to do something more.
+        [ -r "$@" ] || ( cd ${srcdir} && autoheader )
 $(srcdir)/src/stamp-h.in: $(AUTOCONF_INPUTS)
         cd ${srcdir} && autoheader
         rm -f $(srcdir)/src/stamp-h.in
diff --git a/src/Makefile.in b/src/Makefile.in
index c99c7ae65d2..571fbf5b1b1 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -1098,7 +1098,9 @@ tags: TAGS TAGS-LISP $(lwlibdir)TAGS
 /* Since the .el.elc rule cannot specify an extra dependency, we do it here.  */
 ${lisp} ${SOME_MACHINE_LISP}: $(BOOTSTRAPEMACS)
 
-${lispsource}loaddefs.el: $(BOOTSTRAPEMACS)
+/* VCSWITNESS points to the file that holds info about the current checkout.
+   We use it as a heuristic to decide when to rebuild loaddefs.el.  */
+${lispsource}loaddefs.el: $(BOOTSTRAPEMACS) $(VCSWITNESS)
         cd ../lisp; $(MAKE) $(MFLAGS) autoloads EMACS=${bootstrap_exe}
 
 /* Dump an Emacs executable named bootstrap-emacs containing the