gnome: Fix parsing of resource custom target files

gnome.compile_resources() was not parsing custom target sources
properly. It was using the custom target name as the output of the
custom target instead of looking at the list of outputs.

Also modify the GNOME framework test to expose this.

mesonbuild/modules/gnome.py

@@ -259,21 +259,28 @@ class GnomeModule(ExtensionModule):
                 if hasattr(dep, 'held_object'):
                     dep = dep.held_object
                 if isinstance(dep, mesonlib.File):
-                    if dep.fname == missing_basename:
-                        found = True
-                        dep_files.remove(missing)
-                        dep_files.append(dep)
-                        subdirs.append(dep.subdir)
-                        break
+                    if dep.fname != missing_basename:
+                        continue
+                    found = True
+                    dep_files.remove(missing)
+                    dep_files.append(dep)
+                    subdirs.append(dep.subdir)
+                    break
                 elif isinstance(dep, build.CustomTarget):
-                    if dep.get_basename() == missing_basename:
+                    fname = None
+                    outputs = {(o, os.path.basename(o)) for o in dep.get_outputs()}
+                    for o, baseo in outputs:
+                        if baseo == missing_basename:
+                            fname = o
+                            break
+                    if fname is not None:
                         found = True
                         dep_files.remove(missing)
                         dep_files.append(
                             mesonlib.File(
                                 is_built=True,
                                 subdir=dep.get_subdir(),
-                                fname=dep.get_basename()))
+                                fname=fname))
                         depends.append(dep)
                         subdirs.append(dep.get_subdir())
                         break

test cases/frameworks/7 gnome/resources-data/meson.build

@@ -10,7 +10,7 @@ print("This is a generated resource.")
 
 # Generate file res3.txt from file res3.txt.in. This is then included
 # in a GResource file, driven by resources/meson.build.
-res3_txt = custom_target('res3.txt',
+res3_txt = custom_target('res3',
   input: 'res3.txt.in',
   output: 'res3.txt',
   command: [python3, '-c', fake_generator_script, '@INPUT@'],