tests: add reduced version of freebsd gtk+-3.0 crappy output situation as a testcase

Makefile.am

@@ -65,6 +65,10 @@ EXTRA_DIST =	pkg.m4 \
 		tests/lib1/flag-order-1.pc \
 		tests/lib1/flag-order-3.pc \
 		tests/lib1/variable-whitespace.pc \
+		tests/lib1/fragment-collision.pc \
+		tests/lib1/fragment-collision-intermediary.pc \
+		tests/lib1/fragment-collision-1.pc \
+		tests/lib1/fragment-collision-2.pc \
 		tests/lib1/fragment-quoting.pc \
 		tests/lib1/fragment-quoting-2.pc \
 		tests/lib1/fragment-quoting-3.pc \

tests/lib1/fragment-collision-1.pc

@@ -0,0 +1,4 @@
+Name: fragment-collision-1
+Version: 0
+Description: fragment collision test package
+Cflags: -D_THREAD_SAFE -pthread

tests/lib1/fragment-collision-2.pc

@@ -0,0 +1,4 @@
+Name: fragment-collision-2
+Version: 0
+Description: fragment collision test package
+CFlags: -D_FOO

tests/lib1/fragment-collision-intermediary.pc

@@ -0,0 +1,5 @@
+Name: fragment-collision-intermediary
+Version: 0
+Description: fragment collision test package
+Requires.private: fragment-collision-1, fragment-collision-2
+CFlags: -D_BAR

tests/lib1/fragment-collision.pc

@@ -0,0 +1,6 @@
+Name: fragment-collision
+Version: 0
+Description: fragment collision test package
+Requires: fragment-collision-2, fragment-collision-intermediary
+Requires.private: fragment-collision-1
+Cflags: -D_BAZ

tests/regress.sh

@@ -24,7 +24,8 @@ tests_init \
 	idirafter_ordering \
 	pcpath \
 	sysroot_munge \
-	virtual_variable
+	virtual_variable \
+	fragment_collision
 
 case_sensitivity_body()
 {
@@ -217,3 +218,9 @@ virtual_variable_body()
 	atf_check -o inline:"${pcpath}\n" \
 		pkgconf --variable=pc_path pkgconf
 }
+
+fragment_collision_body()
+{
+	atf_check -o inline:"-D_BAZ -D_BAR -D_FOO -D_THREAD_SAFE -pthread \n" \
+		pkgconf --with-path="${selfdir}/lib1" --cflags fragment-collision
+}