if no cflags or libs are defined in .pc just return 0 and output nothing

main.c

@@ -306,15 +306,19 @@ static bool
 apply_cflags(pkg_t *world, void *list_head, int maxdepth, unsigned int flags)
 {
 	pkg_fragment_t **head = list_head;
-	pkg_fragment_t *list;
+	int eflag;
 
-	list = pkg_cflags(world, head, maxdepth, flags | PKGF_SEARCH_PRIVATE);
-	if (list == NULL)
+	eflag = pkg_cflags(world, head, maxdepth, flags | PKGF_SEARCH_PRIVATE);
+	if (eflag != PKG_ERRF_OK)
 		return false;
 
-	print_cflags(list);
+	if (*head == NULL)
+		return true;
+
+	print_cflags(*head);
+
+	pkg_fragment_free(*head);
 
-	pkg_fragment_free(list);
 	return true;
 }
 
@@ -322,14 +326,18 @@ static bool
 apply_libs(pkg_t *world, void *list_head, int maxdepth, unsigned int flags)
 {
 	pkg_fragment_t **head = list_head;
-	pkg_fragment_t *list;
+	int eflag;
 
-	list = pkg_libs(world, head, maxdepth, flags);
-	if (list == NULL)
+	eflag = pkg_libs(world, head, maxdepth, flags);
+	if (eflag != PKG_ERRF_OK)
 		return false;
-	print_libs(list);
 
-	pkg_fragment_free(list);
+	if (*head == NULL)
+		return true;
+
+	print_libs(*head);
+
+	pkg_fragment_free(*head);
 	return true;
 }
 

pkg.c

@@ -853,7 +853,7 @@ pkg_cflags_collect(pkg_t *pkg, void *data, unsigned int flags)
 		*list = pkg_fragment_copy(*list, frag);
 }
 
-pkg_fragment_t *
+int
 pkg_cflags(pkg_t *root, pkg_fragment_t **list, int maxdepth, unsigned int flags)
 {
 	int eflag;
@@ -863,10 +863,10 @@ pkg_cflags(pkg_t *root, pkg_fragment_t **list, int maxdepth, unsigned int flags)
 	if (eflag != PKG_ERRF_OK)
 	{
 		pkg_fragment_free(*list);
-		return NULL;
+		*list = NULL;
 	}
 
-	return *list;
+	return eflag;
 }
 
 static void
@@ -891,7 +891,7 @@ pkg_libs_private_collect(pkg_t *pkg, void *data, unsigned int flags)
 		*list = pkg_fragment_copy(*list, frag);
 }
 
-pkg_fragment_t *
+int
 pkg_libs(pkg_t *root, pkg_fragment_t **list, int maxdepth, unsigned int flags)
 {
 	int eflag;
@@ -901,7 +901,8 @@ pkg_libs(pkg_t *root, pkg_fragment_t **list, int maxdepth, unsigned int flags)
 	if (eflag != PKG_ERRF_OK)
 	{
 		pkg_fragment_free(*list);
-		return NULL;
+		*list = NULL;
+		return eflag;
 	}
 
 	if (flags & PKGF_MERGE_PRIVATE_FRAGMENTS)
@@ -910,9 +911,9 @@ pkg_libs(pkg_t *root, pkg_fragment_t **list, int maxdepth, unsigned int flags)
 		if (eflag != PKG_ERRF_OK)
 		{
 			pkg_fragment_free(*list);
-			return NULL;
+			*list = NULL;
 		}
 	}
 
-	return *list;
+	return eflag;
 }

pkg.h

@@ -134,8 +134,8 @@ unsigned int pkg_verify_graph(pkg_t *root, int depth, unsigned int flags);
 int pkg_compare_version(const char *a, const char *b);
 pkg_t *pkg_verify_dependency(pkg_dependency_t *pkgdep, unsigned int flags, unsigned int *eflags);
 const char *pkg_get_comparator(pkg_dependency_t *pkgdep);
-pkg_fragment_t *pkg_cflags(pkg_t *root, pkg_fragment_t **list, int maxdepth, unsigned int flags);
-pkg_fragment_t *pkg_libs(pkg_t *root, pkg_fragment_t **list, int maxdepth, unsigned int flags);
+int pkg_cflags(pkg_t *root, pkg_fragment_t **list, int maxdepth, unsigned int flags);
+int pkg_libs(pkg_t *root, pkg_fragment_t **list, int maxdepth, unsigned int flags);
 
 /* parse.c */
 pkg_t *pkg_new_from_file(const char *path, FILE *f);

tests/lib1/nocflag.pc

@@ -0,0 +1,9 @@
+prefix=/usr
+exec_prefix=${prefix}
+libdir=${prefix}/lib
+includedir=${prefix}/include
+
+Name: foo
+Description: A testing pkg-config file
+Version: 1.2.3
+Libs: -L${libdir} -lfoo

tests/lib1/nolib.pc

@@ -0,0 +1,9 @@
+prefix=/usr
+exec_prefix=${prefix}
+libdir=${prefix}/lib
+includedir=${prefix}/include
+
+Name: foo
+Description: A testing pkg-config file
+Version: 1.2.3
+Cflags: -fPIC -I${includedir}/foo

tests/run.sh.in

@@ -171,6 +171,12 @@ run_test "PKG_CONFIG_PATH=${selfdir}/lib1 ${1} --cflags missing-require; echo \$
 run_test "PKG_CONFIG_PATH=${selfdir}/lib1 ${1} --cflags quotes" \
 	"-DQUOTED=\\\"bla\\\""
 
+run_test "PKG_CONFIG_PATH=${selfdir}/lib1 ${1} --libs nolib; echo \$?" \
+	'0'
+
+run_test "PKG_CONFIG_PATH=${selfdir}/lib1 ${1} --libs nocflag; echo \$?" \
+	'0'
+
 # 10) tests for internal getopt implementation with options at the end
 if [ "x@STRICT_MODE@" = "xno" ]; then
 	run_test "PKG_CONFIG_PATH=${selfdir}/lib1 ${1} foo --libs" \