Merge pull request #5782 from geky/littlefs-fix-seek-cur

littlefs: Fix positive seek bounds checking

Author: theotherjimmy

features/filesystem/littlefs/littlefs/lfs.c

@@ -1635,13 +1635,13 @@ lfs_soff_t lfs_file_seek(lfs_t *lfs, lfs_file_t *file,
     if (whence == LFS_SEEK_SET) {
         file->pos = off;
     } else if (whence == LFS_SEEK_CUR) {
-        if ((lfs_off_t)-off > file->pos) {
+        if (off < 0 && (lfs_off_t)-off > file->pos) {
             return LFS_ERR_INVAL;
         }
 
         file->pos = file->pos + off;
     } else if (whence == LFS_SEEK_END) {
-        if ((lfs_off_t)-off > file->size) {
+        if (off < 0 && (lfs_off_t)-off > file->size) {
             return LFS_ERR_INVAL;
         }
 

features/filesystem/littlefs/littlefs/tests/test_seek.sh

@@ -133,6 +133,14 @@ tests/test.py << TEST
     lfs_file_read(&lfs, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
+    lfs_file_seek(&lfs, &file[0], 0, LFS_SEEK_CUR) => size;
+    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    memcmp(buffer, "kittycatcat", size) => 0;
+
+    lfs_file_seek(&lfs, &file[0], size, LFS_SEEK_CUR) => 3*size;
+    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    memcmp(buffer, "kittycatcat", size) => 0;
+
     lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => pos;
     lfs_file_read(&lfs, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
@@ -174,6 +182,14 @@ tests/test.py << TEST
     lfs_file_read(&lfs, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
+    lfs_file_seek(&lfs, &file[0], 0, LFS_SEEK_CUR) => size;
+    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    memcmp(buffer, "kittycatcat", size) => 0;
+
+    lfs_file_seek(&lfs, &file[0], size, LFS_SEEK_CUR) => 3*size;
+    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    memcmp(buffer, "kittycatcat", size) => 0;
+
     lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => pos;
     lfs_file_read(&lfs, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;