Allow using files from the pool while importing source packages

Sometimes source packages reference files already present in the pool.

Allow for those file to be omitted when importing packages either via
`repo add` or `repo include`. If file is missing, aptly would make
an attempt to look up file in the package pool (by checksum) and
use it.

Fixes: #278

system/t09_repo/include.py

@@ -516,3 +516,44 @@ class IncludeRepo21Test(BaseTest):
             super(IncludeRepo21Test, self).check()
         finally:
             shutil.rmtree(self.tempSrcDir)
+
+
+class IncludeRepo22Test(BaseTest):
+    """
+    include packages to local repo: missing files, but files aready in the pool
+    """
+    fixtureCmds = [
+        "aptly repo create stable",
+        "aptly repo create unstable",
+        "aptly repo add stable ${changes}"
+    ]
+    runCmd = "aptly repo include -ignore-signatures -keyring=${files}/aptly.pub "
+
+    def outputMatchPrepare(self, s):
+        return gpgRemove(self, tempDirRemove(self, s))
+
+    def prepare(self):
+        super(IncludeRepo22Test, self).prepare()
+
+        self.tempSrcDir = tempfile.mkdtemp()
+        os.makedirs(os.path.join(self.tempSrcDir, "01"), 0755)
+
+        for path in ["hardlink_0.2.1.dsc", "hardlink_0.2.1_amd64.deb"]:
+            shutil.copy(os.path.join(os.path.dirname(inspect.getsourcefile(BaseTest)), "changes", path),
+                        os.path.join(self.tempSrcDir, "01", path))
+
+        path = "hardlink_0.2.1_amd64.changes"
+        with open(os.path.join(os.path.dirname(inspect.getsourcefile(BaseTest)), "changes", path), "r") as source:
+            with open(os.path.join(self.tempSrcDir, "01", path), "w") as dest:
+                content = source.readlines()
+                # remove reference to .tar.gz file
+                content = [line for line in content if "hardlink_0.2.1.tar.gz" not in line]
+                dest.write("".join(content))
+
+        self.runCmd += self.tempSrcDir
+
+    def check(self):
+        try:
+            super(IncludeRepo22Test, self).check()
+        finally:
+            shutil.rmtree(self.tempSrcDir)