Release 7.0.280 blockers: backend writer close order, x64 Linux native swap

.github/workflows/linux-build-run.yml

@@ -238,10 +238,14 @@ jobs:
       # The suite's C build compiles ~7,000 translation units, several of them
       # large, with full debug info. On ubuntu-24.04-arm it exhausted memory and
       # the runner was shut down mid-build, twice at the same step; extra swap
-      # lets the peak spill instead of taking the machine down.
-      - name: Add swap (arm64)
-        if: matrix.arch == 'arm64'
+      # lets the peak spill instead of taking the machine down. x64 joined it once
+      # the suite grew (#6118, #6106): every x64 run since went silent in
+      # `cmake --build` and was shut down about an hour in, while arm64 passed --
+      # the arm64 symptom exactly. `df` is here so a recurrence shows whether the
+      # disk, not memory, is what ran out.
+      - name: Add swap
         run: |
+          df -h /
           free -m
           sudo fallocate -l 12G /cn1-swapfile
           sudo chmod 600 /cn1-swapfile

vm/backend/src/com/codename1/backend/HttpServer.java

@@ -9271,15 +9271,19 @@ private void writeHeadAndBody(Conn conn, int fd, long session, Response response
         }
 
         if (streamed) {
+            // A bodiless response's writer is closed before the head is written, so
+            // the close happens-before anything the client does after reading the
+            // status. Closing it after the write let the client run ahead of it.
+            if (noBody) {
+                response.discard();
+            }
             try {
                 writeTo(fd, session, conn.out, 0, conn.outLength);
             } catch (IOException | RuntimeException headFailed) {
                 response.discard();
                 throw headFailed;
             }
-            if (noBody) {
-                response.discard();
-            } else {
+            if (!noBody) {
                 ResponseOutput output = new ResponseOutput(fd, session, chunked, null, 0); //NOPMD CloseResource - complete flushes on success; failure must abort and the connection owns the socket.
                 response.bodyWriter.writeTo(output);
                 output.complete();