Avoid undefined behavior by ensuring m_path is not empty

dzenanz · dzenanz · commit f1138e84f589 · 2022-01-17T17:04:20.000-05:00
Debug version crashes here, release version optimizes away the check.
diff --git a/include/xtensor-zarr/xzarr_node.hpp b/include/xtensor-zarr/xzarr_node.hpp
@@ -68,7 +68,7 @@ namespace xt
         {
             m_path = '/' + m_path;
         }
-        while (m_path.back() == '/')
+        while (!m_path.empty() && m_path.back() == '/')
         {
             m_path = m_path.substr(0, m_path.size() - 1);
         }

Original file line number	Diff line number	Diff line change
`@@ -68,7 +68,7 @@ namespace xt`
`68`	`68`	`{`
`69`	`69`	`m_path = '/' + m_path;`
`70`	`70`	`}`
`71`		`- while (m_path.back() == '/')`
	`71`	`+ while (!m_path.empty() && m_path.back() == '/')`
`72`	`72`	`{`
`73`	`73`	`m_path = m_path.substr(0, m_path.size() - 1);`
`74`	`74`	`}`