From 8c7b6b26e625ce803cd1ad86a19f1710cbe9bc7f Mon Sep 17 00:00:00 2001
From: Joakim Plate <joakim.plate@rt-labs.com>
Date: Tue, 12 Aug 2025 14:56:29 +0200
Subject: [PATCH] fix: false uninitialized read warning

Add asserts on file system reads to make sure
no positive values are returned, which would
make assumptions on error checks invalid.

This fixes clang tidy warnings on uninitialized
reads in uses of lfs_dir_get where only negative
returns are considered errors.
---
 lfs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lfs.c b/lfs.c
index 624f43cc..4086f00e 100644
--- a/lfs.c
+++ b/lfs.c
@@ -739,6 +739,7 @@ static lfs_stag_t lfs_dir_getslice(lfs_t *lfs, const lfs_mdir_t *dir,
         int err = lfs_bd_read(lfs,
                 NULL, &lfs->rcache, sizeof(ntag),
                 dir->pair[0], off, &ntag, sizeof(ntag));
+        LFS_ASSERT(err <= 0);
         if (err) {
             return err;
         }
@@ -767,6 +768,7 @@ static lfs_stag_t lfs_dir_getslice(lfs_t *lfs, const lfs_mdir_t *dir,
             err = lfs_bd_read(lfs,
                     NULL, &lfs->rcache, diff,
                     dir->pair[0], off+sizeof(tag)+goff, gbuffer, diff);
+            LFS_ASSERT(err <= 0);
             if (err) {
                 return err;
             }