bisect-runner.pl must patch Configure to avoid myread looping infinitely

Configure can get stuck and ask questions for which it needs a valid answer
before it can continue. As-is, if you redirect stdin from /dev/null (or close
the file descriptor) it will (effectively) loop infinitely repeating the same
question, because it doesn't like empty string as an answer. Worse - it keeps
repeating the question to stdout - eg 'Where is your C library?'

Rather than attempting to patch the shell script to detect errors on read
(because they only matter the *second* time round the loop, *and* wouldn't
handle the /dev/null case), it's easier to patch the relevant loop so that
it will abort after too many loop iterations.

1 files changed, 7 insertions, 0 deletions

diff --git a/Porting/bisect-runner.pl b/Porting/bisect-runner.pl
index b8fcb4c9e2..0d32799134 100755
--- a/Porting/bisect-runner.pl
+++ b/Porting/bisect-runner.pl
@@ -2632,6 +2632,13 @@ index 3d2e8b9..6ce7766 100755
  
 EOPATCH
     }
+
+    if ($major < 38 && !extract_from_file('Configure', qr/Too many attempts asking the same question/)) {
+        # Without this, myread can loop infinitely trying to get a valid answer,
+        # and hence Configure gets stuck in a loop, outputting the same question
+        # repeatedly. This isn't what we need.
+        apply_commit('46bfb3c49f22629a');
+    }
 }
 
 sub patch_hints {