Use isAbsolute()

src/libutil/file-system.cc

@@ -31,12 +31,7 @@ namespace nix {
 
 namespace fs { using namespace std::filesystem; }
 
-/**
- * Treat the string as possibly an absolute path, by inspecting the
- * start of it. Return whether it was probably intended to be
- * absolute.
- */
-static bool isAbsolute(PathView path)
+bool isAbsolute(PathView path)
 {
     return fs::path { path }.is_absolute();
 }

src/libutil/file-system.hh

@@ -42,6 +42,11 @@ namespace nix {
 struct Sink;
 struct Source;
 
+/**
+ * Return whether the path denotes an absolute path.
+ */
+bool isAbsolute(PathView path);
+
 /**
  * @return An absolutized path, resolving paths relative to the
  * specified directory, or the current directory otherwise.  The path

src/libutil/source-accessor.cc

@@ -115,7 +115,7 @@ CanonPath SourceAccessor::resolveSymlinks(
                         throw Error("infinite symlink recursion in path '%s'", showPath(path));
                     auto target = readLink(res);
                     res.pop();
-                    if (hasPrefix(target, "/"))
+                    if (isAbsolute(target))
                         res = CanonPath::root;
                     todo.splice(todo.begin(), tokenizeString<std::list<std::string>>(target, "/"));
                 }