Merge pull request #5832 from geky/fix-truncate-zero

littlefs: Fix file truncation without writes

Author: cmonr

features/filesystem/littlefs/littlefs/lfs.c

@@ -1261,6 +1261,9 @@ int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
     file->pos = 0;
 
     if (flags & LFS_O_TRUNC) {
+        if (file->size != 0) {
+            file->flags |= LFS_F_DIRTY;
+        }
         file->head = 0xffffffff;
         file->size = 0;
     }

features/filesystem/littlefs/littlefs/tests/test_files.sh

@@ -34,7 +34,8 @@ tests/test.py << TEST
     lfs_size_t chunk = 31;
     srand(0);
     lfs_mount(&lfs, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "$2", LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    lfs_file_open(&lfs, &file[0], "$2",
+        ${3:-LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC}) => 0;
     for (lfs_size_t i = 0; i < size; i += chunk) {
         chunk = (chunk < size - i) ? chunk : size - i;
         for (lfs_size_t b = 0; b < chunk; b++) {
@@ -53,7 +54,10 @@ tests/test.py << TEST
     lfs_size_t chunk = 29;
     srand(0);
     lfs_mount(&lfs, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "$2", LFS_O_RDONLY) => 0;
+    lfs_stat(&lfs, "$2", &info) => 0;
+    info.type => LFS_TYPE_REG;
+    info.size => size;
+    lfs_file_open(&lfs, &file[0], "$2", ${3:-LFS_O_RDONLY}) => 0;
     for (lfs_size_t i = 0; i < size; i += chunk) {
         chunk = (chunk < size - i) ? chunk : size - i;
         lfs_file_read(&lfs, &file[0], buffer, chunk) => chunk;
@@ -78,10 +82,27 @@ echo "--- Large file test ---"
 w_test $LARGESIZE largeavacado
 r_test $LARGESIZE largeavacado
 
+echo "--- Zero file test ---"
+w_test 0 noavacado
+r_test 0 noavacado
+
+echo "--- Truncate small test ---"
+w_test $SMALLSIZE mediumavacado
+r_test $SMALLSIZE mediumavacado
+w_test $MEDIUMSIZE mediumavacado
+r_test $MEDIUMSIZE mediumavacado
+
+echo "--- Truncate zero test ---"
+w_test $SMALLSIZE noavacado
+r_test $SMALLSIZE noavacado
+w_test 0 noavacado
+r_test 0 noavacado
+
 echo "--- Non-overlap check ---"
 r_test $SMALLSIZE smallavacado
 r_test $MEDIUMSIZE mediumavacado
 r_test $LARGESIZE largeavacado
+r_test 0 noavacado
 
 echo "--- Dir check ---"
 tests/test.py << TEST
@@ -105,6 +126,10 @@ tests/test.py << TEST
     strcmp(info.name, "largeavacado") => 0;
     info.type => LFS_TYPE_REG;
     info.size => $LARGESIZE;
+    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    strcmp(info.name, "noavacado") => 0;
+    info.type => LFS_TYPE_REG;
+    info.size => 0;
     lfs_dir_read(&lfs, &dir[0], &info) => 0;
     lfs_dir_close(&lfs, &dir[0]) => 0;
     lfs_unmount(&lfs) => 0;