fix(phone-api): skip manifest scan for node-info-only requests; bound getFiles (#10778)

Forward-port of #10754 and #10757 from master (2.7) into develop, so the
develop->master 2.8 promotion (#10777) doesn't drop them.

#10754: PhoneAPI no longer walks the filesystem to build the file manifest on
node-info-only config requests (SPECIAL_NONCE_ONLY_NODES), which never consume
it. getFiles() is now bounded (default 64 entries, depth 3) via collectFiles(),
takes an optional wasLimited out-param, and reserves capacity with a bad_alloc/
length_error fallback. The manifest vector is freed via swap (releaseFilesManifest).

#10757: getFiles()/collectFiles() now guard against empty file names returned by
the Adafruit LittleFS nRF52 glue (issue 4395).

Ported by hand rather than cherry-picked: master had reflowed FSCommon.cpp to a
different brace style (every line conflicted), #10754 already subsumes #10757,
and develop carries a MESHTASTIC_EXCLUDE_FILES_MANIFEST path (nRF54L15) that
master lacks. The exclude path is preserved and now also short-circuits + frees
the manifest. Verified: native Docker suite 448/448, clang-format clean.

src/FSCommon.cpp

@@ -88,6 +88,9 @@ bool renameFile(const char *pathFrom, const char *pathTo)
 #endif
 }
 
+#include <cstring>
+#include <new>
+#include <stdexcept>
 #include <vector>
 
 /**
@@ -119,6 +122,93 @@ bool fsFormat()
 #endif
 }
 
+#ifdef FSCom
+namespace
+{
+bool pathEndsWithDot(const char *path)
+{
+    if (!path)
+        return false;
+
+    size_t length = strlen(path);
+    return length > 0 && path[length - 1] == '.';
+}
+
+bool copyFilePath(char *dest, size_t destSize, const char *path, bool *wasLimited)
+{
+    if (!path || destSize == 0) {
+        if (wasLimited)
+            *wasLimited = true;
+        return false;
+    }
+
+    if (strlcpy(dest, path, destSize) >= destSize) {
+        if (wasLimited)
+            *wasLimited = true;
+        return false;
+    }
+
+    return true;
+}
+
+void collectFiles(const char *dirname, uint8_t levels, size_t maxCount, std::vector<meshtastic_FileInfo> &filenames,
+                  bool *wasLimited)
+{
+    if (!dirname)
+        return;
+
+    File root = FSCom.open(dirname, FILE_O_READ);
+    if (!root)
+        return;
+    if (!root.isDirectory()) {
+        root.close();
+        return;
+    }
+
+    File file = root.openNextFile();
+    // file.name()[0] check is a workaround for a bug in the Adafruit LittleFS nrf52 glue (see issue 4395)
+    while (file && file.name()[0]) {
+        if (filenames.size() >= maxCount) {
+            if (wasLimited)
+                *wasLimited = true;
+            file.close();
+            break;
+        }
+        const char *fileName = file.name();
+        if (file.isDirectory() && !pathEndsWithDot(fileName)) {
+            char pathBuffer[sizeof(((meshtastic_FileInfo *)nullptr)->file_name)] = {};
+#ifdef ARCH_ESP32
+            const char *subDirPath = file.path();
+#else
+            const char *subDirPath = fileName;
+#endif
+            bool hasSubDirPath = copyFilePath(pathBuffer, sizeof(pathBuffer), subDirPath, wasLimited);
+            file.close();
+
+            if (levels && hasSubDirPath) {
+                collectFiles(pathBuffer, levels - 1, maxCount, filenames, wasLimited);
+            } else if (wasLimited) {
+                *wasLimited = true;
+            }
+        } else {
+            meshtastic_FileInfo fileInfo = {"", static_cast<uint32_t>(file.size())};
+#ifdef ARCH_ESP32
+            bool hasFilePath = copyFilePath(fileInfo.file_name, sizeof(fileInfo.file_name), file.path(), wasLimited);
+#else
+            bool hasFilePath = copyFilePath(fileInfo.file_name, sizeof(fileInfo.file_name), file.name(), wasLimited);
+#endif
+            if (hasFilePath && !pathEndsWithDot(fileInfo.file_name)) {
+                filenames.push_back(fileInfo);
+            }
+            file.close();
+        }
+        file = root.openNextFile();
+    }
+    root.close();
+}
+} // namespace
+#endif
+
 /**
  * @brief Get the list of files in a directory.
  *
@@ -127,43 +217,40 @@ bool fsFormat()
  *
  * @param dirname The name of the directory.
  * @param levels The number of levels of subdirectories to list.
- * @return A vector of strings containing the full path of each file in the directory.
+ * @param maxCount The maximum number of files to collect before truncating the walk.
+ * @param wasLimited Optional out-param, set to true if the listing was truncated (by maxCount or low memory).
+ * @return A vector of meshtastic_FileInfo for each file in the directory.
  */
-std::vector<meshtastic_FileInfo> getFiles(const char *dirname, uint8_t levels)
+std::vector<meshtastic_FileInfo> getFiles(const char *dirname, uint8_t levels, size_t maxCount, bool *wasLimited)
 {
     std::vector<meshtastic_FileInfo> filenames = {};
+    if (wasLimited)
+        *wasLimited = false;
 #ifdef FSCom
-    File root = FSCom.open(dirname, FILE_O_READ);
+#if defined(__cpp_exceptions) || defined(__EXCEPTIONS)
-    if (!root)
+    size_t reservedCount = maxCount;
-        return filenames;
+    while (reservedCount > 0) {
-    if (!root.isDirectory())
+        try {
-        return filenames;
+            filenames.reserve(reservedCount);
-
+            break;
-    File file = root.openNextFile();
+        } catch (const std::bad_alloc &) {
-    while (file) {
+            reservedCount /= 2;
-#ifdef ARCH_ESP32
+        } catch (const std::length_error &) {
-        const char *filepath = file.path();
+            reservedCount /= 2;
-#else
-        const char *filepath = file.name();
-#endif
-        if (file.isDirectory() && !String(file.name()).endsWith(".")) {
-            if (levels) {
-                std::vector<meshtastic_FileInfo> subDirFilenames = getFiles(filepath, levels - 1);
-                filenames.insert(filenames.end(), subDirFilenames.begin(), subDirFilenames.end());
-                file.close();
-            }
-        } else {
-            meshtastic_FileInfo fileInfo = {"", static_cast<uint32_t>(file.size())};
-            strncpy(fileInfo.file_name, filepath, sizeof(fileInfo.file_name) - 1);
-            fileInfo.file_name[sizeof(fileInfo.file_name) - 1] = '\0';
-            if (!String(fileInfo.file_name).endsWith(".")) {
-                filenames.push_back(fileInfo);
-            }
-            file.close();
         }
-        file = root.openNextFile();
     }
-    root.close();
+    if (reservedCount == 0) {
+        if (wasLimited)
+            *wasLimited = true;
+        return filenames;
+    }
+    if (reservedCount < maxCount) {
+        if (wasLimited)
+            *wasLimited = true;
+        maxCount = reservedCount;
+    }
+#endif
+    collectFiles(dirname, levels, maxCount, filenames, wasLimited);
 #endif
     return filenames;
 }

src/FSCommon.h

@@ -61,7 +61,7 @@ void fsListFiles();
 bool copyFile(const char *from, const char *to);
 bool renameFile(const char *pathFrom, const char *pathTo);
 bool fsFormat();
-std::vector<meshtastic_FileInfo> getFiles(const char *dirname, uint8_t levels);
+std::vector<meshtastic_FileInfo> getFiles(const char *dirname, uint8_t levels, size_t maxCount = 64, bool *wasLimited = nullptr);
 void listDir(const char *dirname, uint8_t levels, bool del = false);
 void rmDir(const char *dirname);
 void setupSDCard();

src/mesh/PhoneAPI.cpp

@@ -40,6 +40,17 @@
 #include "Throttle.h"
 #include <RTC.h>
 
+namespace
+{
+constexpr uint8_t FILES_MANIFEST_LEVELS = 3;
+constexpr size_t FILES_MANIFEST_MAX_COUNT = 64;
+
+void releaseFilesManifest(std::vector<meshtastic_FileInfo> &filesManifest)
+{
+    std::vector<meshtastic_FileInfo>().swap(filesManifest);
+}
+} // namespace
+
 // Flag to indicate a heartbeat was received and we should send queue status
 bool heartbeatReceived = false;
 
@@ -298,18 +309,31 @@ void PhoneAPI::handleStartConfig()
         state = STATE_SEND_MY_INFO;
     }
     pauseBluetoothLogging = true;
-    spiLock->lock();
 #if defined(MESHTASTIC_EXCLUDE_FILES_MANIFEST)
     // Skip the recursive FS walk. Used by platforms whose Zephyr LittleFS
     // backend can't safely traverse a deep tree (e.g. nRF54L15) and platforms
     // that don't support OTA browsing — the manifest is only consumed by
     // companion apps for those flows.
-    filesManifest.clear();
+    releaseFilesManifest(filesManifest);
 #else
-    filesManifest = getFiles("/", 10);
+    // Manifest is never read on the node-info-only path (STATE_SEND_FILEMANIFEST
+    // short-circuits to sendConfigComplete), so skip the SPI lock + FS walk.
+    if (config_nonce != SPECIAL_NONCE_ONLY_NODES) {
+        bool filesManifestLimited = false;
+        {
+            concurrency::LockGuard guard(spiLock);
+            filesManifest = getFiles("/", FILES_MANIFEST_LEVELS, FILES_MANIFEST_MAX_COUNT, &filesManifestLimited);
+        }
+        if (filesManifestLimited) {
+            LOG_WARN("Got %zu files in manifest (limited to %zu entries/depth %u)", filesManifest.size(),
+                     FILES_MANIFEST_MAX_COUNT, static_cast<unsigned>(FILES_MANIFEST_LEVELS));
+        } else {
+            LOG_DEBUG("Got %zu files in manifest", filesManifest.size());
+        }
+    } else {
+        releaseFilesManifest(filesManifest);
+    }
 #endif
-    spiLock->unlock();
-    LOG_DEBUG("Got %d files in manifest", filesManifest.size());
 
     LOG_INFO("Start API client config millis=%u", millis());
     // Protect against concurrent BLE callbacks: they run in NimBLE's FreeRTOS task and also touch nodeInfoQueue.
@@ -377,8 +401,7 @@ void PhoneAPI::close()
             replayPhase = REPLAY_PHASE_IDLE;
         }
         packetForPhone = NULL;
-        filesManifest.clear();
+        releaseFilesManifest(filesManifest);
-        filesManifest.shrink_to_fit();
         lastPortNumToRadio.clear();
         fromRadioNum = 0;
         config_nonce = 0;
@@ -943,7 +966,7 @@ size_t PhoneAPI::getFromRadio(uint8_t *buf)
         // ONLY_NODES variants skip the manifest.
         if (config_state == filesManifest.size() || config_nonce == SPECIAL_NONCE_ONLY_NODES) {
             config_state = 0;
-            filesManifest.clear();
+            releaseFilesManifest(filesManifest);
             // Skip to complete packet
             sendConfigComplete();
         } else {