strings are stored as length+text and NULL byte is not a terminator

src/runtime/c/text.cxx

@@ -0,0 +1,19 @@
+#include "data.h"
+
+PGF_INTERNAL
+int textcmp(PgfText &t1, PgfText &t2)
+{
+    for (size_t i = 0; ; i++) {
+        if (i >= t1.size)
+            return (i - t2.size);
+        if (i >= t2.size)
+            return 1;
+
+        if (t1.text[i] > t2.text[i])
+            return 1;
+        else if (t1.text[i] < t2.text[i])
+            return -1;
+
+        i++;
+    }
+}