Git Bug Fixes and Enhancements

status of the hook. * A failure to push due to non-ff while on an unborn branch dereferenced a NULL pointer when showing an error message. * When users spell "cc:" in lowercase in the fake "header" in the trailer part, "git send-email" failed to pick up the addresses from there. As e-mail headers field names are case insensitive, this script should follow suit and treat "cc:" and "Cc:" the same way. * Output from "git status --ignored" showed an unexpected interaction with "--untracked". * "gitweb", when sorting by age to show repositories with new activities first, used to sort repositories with absolutely nothing in it early, which was not very useful. * "gitweb"'s code to sanitize control characters before passing it to "highlight" filter lost known-to-be-safe control characters by mistake. * "gitweb" pages served over HTTPS, when configured to show picon or gravatar, referred to these external resources to be fetched via HTTP, resulting in mixed contents warning in browsers. * When a line to be wrapped has a solid run of non space characters whose length exactly is the wrap width, "git shortlog -w" failed to add a newline after such a line. * Command line completion leaked an unnecessary error message while looking for possible matches with paths in <tree-ish>. * Command line completion for "tcsh" emitted an unwanted space after completing a single directory name. * Command line completion code was inadvertently made incompatible with older versions of bash by using a newer array notation. * "git push" was taught to refuse updating the branch that is currently checked out long time ago, but the user manual was left stale. (merge 50995ed wk/man-deny-current-branch-is-default-these-days later to maint). * Some shells do not behave correctly when IFS is unset; work it around by explicitly setting it to the default value. * Some scripted programs written in Python did not get updated when PYTHON_PATH changed. (cherry-pick 96a4647fca54031974cd6ad1 later to maint). * When autoconf is used, any build on a different commit always ran "config.status --recheck" even when unnecessary. * A fix was added to the build procedure to work around buggy versions

This release addresses various issues in Git, including fixes for 'git send-email', 'git status', 'gitweb', and command line completion. Additionally, improvements are made to 'git push', 'git shortlog', and the build procedure. Compatibility issues with older bash versions and buggy autoconf versions are also resolved. Other fixes and enhancements include correcting mixed content warnings, improving handling of non-ff pushes, and updating user manuals to reflect current default behavior.