libtextstyle: Don't erase the .sym.in file if 'sed' is not GNU sed.

* libtextstyle/lib/Makefile.am (libtextstyle.sym.in): Test the exit status of
the declared.sh command. Preserve the existing libtextstyle.sym if it failed.

diff --git a/libtextstyle/lib/Makefile.am b/libtextstyle/lib/Makefile.am
index 1b182a02fe5921ed9d4e4c10686802661fc54300..ac9a0fe4212e5eb8c4d83346dfcb2e4d375e1a18 100644 (file)
--- a/libtextstyle/lib/Makefile.am
+++ b/libtextstyle/lib/Makefile.am
@@ -149,16 +149,24 @@ HEADERS_WITH_EXTERNS = \
 # '-export-symbols', but we don't use this option, because it may prevent us
 # from building some of the unit tests.
 $(srcdir)/libtextstyle.sym.in : $(HEADERS_WITH_EXTERNS)
-       for f in $(HEADERS_WITH_EXTERNS); do \
-         if test -f $$f; then \
-           cat $$f; \
+       if \
+         for f in $(HEADERS_WITH_EXTERNS); do \
+           if test -f $$f; then \
+             cat $$f; \
+           else \
+             cat $(srcdir)/$$f; \
+           fi; \
+         done \
+         | $(srcdir)/declared.sh > $@-t1; \
+       then \
+         LC_ALL=C sort < $@-t1 | LC_ALL=C uniq > $@-t2 && mv $@-t2 $@; \
+       else \
+         if test -f $@; then \
+           echo "Continuing with existing libtextstyle.sym.in."; \
          else \
-           cat $(srcdir)/$$f; \
+           exit 1; \
          fi; \
-       done \
-         | $(srcdir)/declared.sh | LC_ALL=C sort | LC_ALL=C uniq \
-         > $@-t
-       mv $@-t $@
+       fi
 # We distribute it because declared.sh relies on GNU sed.
 # The GNU Coding Standards say in
 # <https://www.gnu.org/prep/standards/html_node/Makefile-Basics.html>:
@@ -168,7 +176,7 @@ $(srcdir)/libtextstyle.sym.in : $(HEADERS_WITH_EXTERNS)
 #    So Makefile rules to update them should put the updated files in the
 #    source directory."
 # Therefore we put this file in the source directory, not the build directory.
-MOSTLYCLEANFILES     += libtextstyle.sym.in-t
+MOSTLYCLEANFILES     += libtextstyle.sym.in-t1 libtextstyle.sym.in-t2
 MAINTAINERCLEANFILES += libtextstyle.sym.in
 EXTRA_DIST           += libtextstyle.sym.in declared.sh