Accept both lower and upper case y/n as valid answers in yn_prompt()

2 files changed, 6 insertions, 2 deletions

diff --git a/libbutl/prompt.cxx b/libbutl/prompt.cxx
index 2e42dd5..154522c 100644
--- a/libbutl/prompt.cxx
+++ b/libbutl/prompt.cxx
@@ -44,8 +44,8 @@ namespace butl
         if (!e)
           a = def;
       }
-    } while (a != "y" && a != "n");
+    } while (a != "y" && a != "Y" && a != "n" && a != "N");
 
-    return a == "y";
+    return a == "y" || a == "Y";
   }
 }
diff --git a/libbutl/prompt.hxx b/libbutl/prompt.hxx
index 90b8dbf..2a07708 100644
--- a/libbutl/prompt.hxx
+++ b/libbutl/prompt.hxx
@@ -15,6 +15,10 @@ namespace butl
   // Write the prompt to diag_stream. Throw ios_base::failure if no answer
   // could be extracted from stdin (for example, because it was closed).
   //
+  // Note that the implementation accepts both lower and upper case y/n as
+  // valid answers (apparently the capitalized default answer confuses some
+  // users into answering with capital letters).
+  //
   LIBBUTL_SYMEXPORT bool
   yn_prompt (const std::string&, char def = '\0');
 }