From cee01f171a505cc91dcfa2f1ecb9c9f6e2a9bd17 Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Sat, 7 Jul 2018 12:51:32 +0200
Subject: Move prompt facility from bpkg to libbutl

---
 bpkg/utility.cxx    | 43 +++++++++----------------------------------
 bpkg/utility.hxx    | 10 +++++-----
 tests/rep-auth.test |  8 ++++----
 3 files changed, 18 insertions(+), 43 deletions(-)

diff --git a/bpkg/utility.cxx b/bpkg/utility.cxx
index 8a456d0..c6f2fae 100644
--- a/bpkg/utility.cxx
+++ b/bpkg/utility.cxx
@@ -6,6 +6,7 @@
 
 #include <iostream>     // cout, cin
 
+#include <libbutl/prompt.mxx>
 #include <libbutl/process.mxx>
 #include <libbutl/fdstream.mxx>
 
@@ -85,42 +86,16 @@ namespace bpkg
   bool stderr_term;
 
   bool
-  yn_prompt (const char* prompt, char def)
+  yn_prompt (const string& p, char d)
   {
-    // Writing a robust Y/N prompt is more difficult than one would
-    // expect...
-    //
-    string a;
-    do
+    try
     {
-      *diag_stream << prompt << ' ';
-
-      // getline() will set the failbit if it failed to extract anything,
-      // not even the delimiter and eofbit if it reached eof before seeing
-      // the delimiter.
-      //
-      getline (cin, a);
-
-      bool f (cin.fail ());
-      bool e (cin.eof ());
-
-      if (f || e)
-        *diag_stream << endl; // Assume no delimiter (newline).
-
-      if (f)
-        fail << "unable to read y/n answer from STDOUT";
-
-      if (a.empty () && def != '\0')
-      {
-        // Don't treat eof as the default answer. We need to see the
-        // actual newline.
-        //
-        if (!e)
-          a = def;
-      }
-    } while (a != "y" && a != "n");
-
-    return a == "y";
+      return butl::yn_prompt (p, d);
+    }
+    catch (io_error&)
+    {
+      fail << "unable to read y/n answer from stdin";
+    }
   }
 
   bool
diff --git a/bpkg/utility.hxx b/bpkg/utility.hxx
index 19d664e..c0c361f 100644
--- a/bpkg/utility.hxx
+++ b/bpkg/utility.hxx
@@ -88,13 +88,13 @@ namespace bpkg
   //
   extern bool stderr_term; // True if stderr is a terminal.
 
-  // Y/N prompt. The def argument, if specified, should be either 'y'
-  // or 'n'. It is used as the default answer, in case the user just
-  // hits enter. Issue diagnostics and throw failed if no answer could
-  // be extracted from STDOUT (e.g., because it was closed).
+  // Y/N prompt. See butl::yn_prompt() for details (this is a thin wrapper).
+  //
+  // Issue diagnostics and throw failed if no answer could be extracted from
+  // stdin (e.g., because it was closed).
   //
   bool
-  yn_prompt (const char* prompt, char def = '\0');
+  yn_prompt (const string& prompt, char def = '\0');
 
   // Filesystem.
   //
diff --git a/tests/rep-auth.test b/tests/rep-auth.test
index e27aae2..640f828 100644
--- a/tests/rep-auth.test
+++ b/tests/rep-auth.test
@@ -183,7 +183,7 @@ sc = " " # Space character to append to here-document line when required.
         certificate SHA256 fingerprint:
         $cert_fp
         trust this certificate? [y/n]$sc
-        error: unable to read y/n answer from STDOUT
+        error: unable to read y/n answer from stdin
         EOE
 
       $not_fetched
@@ -293,7 +293,7 @@ sc = " " # Space character to append to here-document line when required.
       certificate SHA256 fingerprint:
       $cert_fp
       trust this certificate? [y/n]$sc
-      error: unable to read y/n answer from STDOUT
+      error: unable to read y/n answer from stdin
       EOE
 
     : trust-fp
@@ -457,7 +457,7 @@ sc = " " # Space character to append to here-document line when required.
         fetching pkg:build2.org/rep-auth/unsigned1
         warning: repository pkg:build2.org/rep-auth/unsigned1 is unsigned
         %continue without authenticating repositories at .+\? \[y/n\] %
-        error: unable to read y/n answer from STDOUT
+        error: unable to read y/n answer from stdin
         EOE
 
       $not_fetched
@@ -535,7 +535,7 @@ sc = " " # Space character to append to here-document line when required.
     $rep_info 2>>~%EOE% != 0
       warning: repository pkg:build2.org/rep-auth/unsigned1 is unsigned
       %continue without authenticating repositories at .+\? \[y/n\] %
-      error: unable to read y/n answer from STDOUT
+      error: unable to read y/n answer from stdin
       EOE
 
     : trust-yes
-- 
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