Guard the web-logbook upload handler against a missing file1 part

[patrickrb]

Root cause

The always-on web logbook server (LogHttpServer, started unconditionally at app launch and reachable on the LAN) handles ADIF uploads at /IMPORTLOGDATA. doImportLogFile read the multipart upload as:

String param = files.get("file1");
ImportTaskList.ImportTask task = importTaskList.addTask(param.hashCode()); // NPE if param == null

IHTTPSession.parseBody(files) only inserts a "file1" entry when the POST/PUT actually carries a file field with that name. A malformed or non-form request — or a bare LAN probe of the logbook port — leaves the map without the key, so param is null and param.hashCode() throws NullPointerException.

That NullPointerException is thrown in the leading dispatch chain of serve() (line ~221), which runs before serve()'s own try/catch (which starts further down and only catches IOException | ResponseException anyway). The throw therefore escapes serve() entirely. NanoHTTPD's worker (ClientHandler.run()) catches it in its generic catch (Exception) and logs "Communication with the client broken", so it is not an app crash — the request is aborted with no useful response.

This is the last unguarded external-input deref in a file whose siblings were already hardened:

• missing path segment uriList[2] → uriSegment(...) (PR Guard web-logger uriList[2] reads so a missing month segment can't crash the handler #584)
• malformed ?page=/?pageSize=/?session= params → parseQueryInt(...) / clampPageIndex(...) (PR Harden web-logbook server against malformed pagination query params #585)

Fix

• Extract a bounds-safe static helper uploadedFilePath(Map<String,String> files) that returns the file1 temp-file path, or null when the part is absent (also null-safe on a null map). This mirrors the existing uriSegment / parseQueryInt static guards and keeps the decision logic unit-testable per the project's Compose/JNI-free testing rule.
• Reject a null result with the existing R.string.html_illegal_command page — the same fallback a non-POST method already returns — instead of dereferencing it.

Well-formed uploads are byte-for-byte identical: a present file1 flows through unchanged.

Testing performed

• New LogHttpServerUploadPartTest — pure-JVM (no Robolectric), mirroring LogHttpServerUriSegmentTest / LogHttpServerQueryParamTest. Covers present part, missing part, wrong field name, null map, and empty-string path (which must stay "present", since the downstream LogFileImport opens it and fails with a caught FileNotFoundException).
• ./gradlew :app:testDebugUnitTest — full suite green.
• ./gradlew :app:assembleDebug — green (all 4 ABIs, incl. native/hamlib build).

Risk assessment

Very low. Pure Java, one added null-guard on an error path plus a thin extracted helper; no protocol, DSP, threading, or native changes; no behavior change for well-formed requests. LAN-facing reliability (category-2) hardening — completes the LogHttpServer external-input sweep.

Affected platforms

Android (the web-logbook server is Android-only).

[Copilot]

Pull request overview

This PR hardens the LAN-reachable LogHttpServer /IMPORTLOGDATA upload handler against malformed multipart requests that omit the file1 upload part, preventing an uncaught NullPointerException during request dispatch and returning a consistent “illegal command” response instead.

Changes:

• Added LogHttpServer.uploadedFilePath(Map<String,String>) to safely fetch the file1 temp-file path (null-safe).
• Updated doImportLogFile to reject missing file1 uploads with the existing html_illegal_command page instead of dereferencing null.
• Added a pure-JVM unit test covering present/missing/wrong-name/null-map/empty-path cases for the new helper.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
ft8af/app/src/main/java/com/k1af/ft8af/html/LogHttpServer.java	Adds a null-safe upload-part helper and uses it to guard /IMPORTLOGDATA against missing file1 parts.
ft8af/app/src/test/java/com/k1af/ft8af/html/LogHttpServerUploadPartTest.java	Adds pure-JVM regression tests pinning the new upload-part guard behavior.

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