protobuf module: fix truncation issue when unpacking (#2800)

It is possible that unpacked files from the classpath share the same name but not the same content. In case an existing unpacked file is replaced by a shorter file, it needs to be properly truncated lest the result be garbage. A warning messages is logged when a proto file gets overwritten. Pull request: #2800 Co-authored-by: Tobias Roeser <[email protected]>
com-lihaoyi · Oct 1, 2023 · b95cf46 · b95cf46
1 parent f0b423e
commit b95cf46
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/contrib/scalapblib/src/mill/contrib/scalapblib/ScalaPBModule.scala b/contrib/scalapblib/src/mill/contrib/scalapblib/ScalaPBModule.scala
@@ -104,7 +104,11 @@ trait ScalaPBModule extends ScalaModule {
             case Some(entry) =>
               if (entry.getName.endsWith(".proto")) {
                 val protoDest = dest / os.SubPath(entry.getName)
-                Using(os.write.outputStream(protoDest, createFolders = true))(IO.stream(zip, _))
+                if (os.exists(protoDest))
+                  T.log.error(s"Warning: Overwriting ${dest} / ${os.SubPath(entry.getName)} ...")
+                Using.resource(os.write.over.outputStream(protoDest, createFolders = true)) { os =>
+                  IO.stream(zip, os)
+                }
               }
               zip.closeEntry()
               true