don't throw an exception for the trivial case of isStorePath()...

Previously if isStorePath() was called on anything other than a
top-level /nix/store/some-path, it would throw a BadStorePath exception.
This commit duplicates the absolutely trivial check, into
maybeParseStorePath(), and leaves exception throwing to
parseStorePath(), the function that assumes you're already giving a
valid path instead of the one whose purpose is to check if its valid or
not...

Change-Id: I8dda548f0f88d14ca8c3ee927d64e0ec0681fc7b

1 files changed, 5 insertions, 0 deletions

diff --git a/src/libstore/path.cc b/src/libstore/path.cc
index c896ff927..2f929b7b3 100644
--- a/src/libstore/path.cc
+++ b/src/libstore/path.cc
@@ -64,6 +64,11 @@ StorePath Store::parseStorePath(std::string_view path) const
 
 std::optional<StorePath> Store::maybeParseStorePath(std::string_view path) const
 {
+    // If it's not an absolute path, or if the dirname of the path isn't /nix/store
+    // (or whatever our storeDir is), then it can't be a store path.
+    if ((path.size() > 0 && path[0] != '/') || dirOf(canonPath(path)) != this->storeDir) {
+        return std::nullopt;
+    }
     try {
         return parseStorePath(path);
     } catch (Error &) {