Here's the patch I promised over on HACKERS - it alters the

implementation
of '\e' history tracking for systems that have a readline compatability
library without replace_history_entry.  I fall back to pushing the query
onto the history stack after the \e, rather than replacing it.

The patch adds one more place to look for readline headers, and a test
for replace_history_entry. I've only included the patch for configure.in

Ross J. Reedstrom