1 files changed, 14 insertions, 3 deletions
diff --git a/configure b/configure
index 4f42953..35a0743 100755
--- a/configure
+++ b/configure
@@ -177,7 +177,7 @@ EOF
 if [ $build_thumbnail -ne 0 ]
 then
 cat <<"EOF" >> $F
-	+cd thumbnail && $(MAKE) PREFIX=$(PREFIX) install
+	+test -f $(THUMBNAIL_MK) && cd thumbnail && $(MAKE) install || :
 EOF
 fi
 
@@ -218,9 +218,13 @@ if [ $build_thumbnail -ne 0 ]
 then
 cat <<"EOF" >> $F
 THUMBNAIL = thumbnail/thumbnail
+THUMBNAIL_MK = thumbnail/Makefile
 thumbnail $(PROJECT): $(THUMBNAIL)
-$(THUMBNAIL): FORCE
+$(THUMBNAIL_MK):
+	cd thumbnail && CFLAGS="$(CFLAGS)" ./configure --prefix=$(PREFIX)
+$(THUMBNAIL): $(THUMBNAIL_MK) FORCE
 	+cd thumbnail && $(MAKE) CC=$(CC)
+all: $(THUMBNAIL)
 EOF
 fi
 
@@ -250,6 +254,13 @@ cat <<"EOF" >> $F
 EOF
 fi
 
+if [ $build_thumbnail -ne 0 ]
+then
+cat <<"EOF" >> $F
+	+test -f $(THUMBNAIL_MK) && cd thumbnail && $(MAKE) clean || :
+EOF
+fi
+
 cat <<"EOF" >> $F
 distclean: clean
 	rm -f slcl usergen
@@ -275,7 +286,7 @@ fi
 if [ $build_thumbnail -ne 0 ]
 then
 cat <<"EOF" >> $F
-	+cd thumbnail && $(MAKE) distclean
+	+test -f $(THUMBNAIL_MK) && cd thumbnail && $(MAKE) distclean || :
 EOF
 fi