[PATCH v6 07/10] of/overlay: don't create "//" paths for fragments targeting the root

dup_and_fixup_symbol_prop() rewrites a symbol value by replacing its
"/fragment/__overlay__" prefix with the fragment's target path. When
the fragment targets the root node the target path is "/" and the
result starts with "//", which __of_find_node_by_full_path() cannot
resolve: symbols pointing into such fragments silently stop
resolving.

Drop the target path when it is the root and the tail is non-empty. A
value naming the fragment root itself (empty tail) keeps the "/".

Fixes: d1651b03c2df ("of: overlay: add overlay symbols to live device tree")
Assisted-by: Claude:claude-fable-5 [Claude Code]
Signed-off-by: Abdurrahman Hussain <[email protected]>
---
 drivers/of/overlay.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index 9b9f198a1d70..89a9fe6d6e78 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -256,6 +256,9 @@ static struct property *dup_and_fixup_symbol_prop(
 	if (!target_path)
 		return NULL;
 	target_path_len = strlen(target_path);
+	/* a root target renders as "/"; drop it to avoid "//" results */
+	if (target_path_len == 1 && target_path[0] == '/' && path_tail_len)
+		target_path_len = 0;
 
 	new_prop = kzalloc_obj(*new_prop);
 	if (!new_prop)

-- 
2.54.0