Ensure that help page manifest is not empty.

For some reason I have found that sometimes doc/help-pages-list
is zero bytes long.   I don't know how this happens, but this
change should catch it and allow us to find out why.

diff --git a/src/ui/gui/automake.mk b/src/ui/gui/automake.mk
index e991eb2e47532e125c5151467f4ade270cc5249e..3f3303fc14de3d99a809a6376dce52f26661edf7 100644 (file)
--- a/src/ui/gui/automake.mk
+++ b/src/ui/gui/automake.mk
@@ -54,7 +54,9 @@ UI_FILES = \
 $(top_srcdir)/doc/help-pages-list: $(UI_FILES)
         $(AM_V_GEN)cat $^ | grep '"help[-_]page"' | \
    $(SED) -e 's% *<property name="help[-_]page">\([^<]*\)</property>%//*[@id='"'"'\1'"'"']%' \
-       -e 's%#%'"'"']/*[@id='"'"'%g' > $@
+       -e 's%#%'"'"']/*[@id='"'"'%g' > $@,tmp
+       test -s $@,tmp
+       mv $@,tmp $@
 
 EXTRA_DIST += doc/help-pages-list