Fix printing the branch used in Git

... and prefer exact specified name, if it exists.
More bootstrap script specifications for packages.

Signed-off-by: Alexey Neyman <stilor@att.net>

TODO

@@ -2,8 +2,18 @@ TBD
 packages todo
 [ ] mention custom glibc addons are no longer handled (even though they never fully were, ct-ng would be unable to fetch them unless they were secretly placed into the download area)
 [ ] mention incompatibility of sample options
-[ ] version-locked packages
+[X] version-locked packages
-  [ ] make glibc-ports package for glibc <2.17 (it has its own repo)
+  [X] make glibc-ports package for glibc <2.17 (it has its own repo)
+[ ] convert gen-kconfig to use templates
+[ ] switch to checked in generated files (config/versions, config/gen) - take too long to generate
+[ ] new packages
+  [ ] config.guess
+  [ ] gnulib
+    [ ] use gnulib in m4, gettext, libiconv, libtool
+  [ ] autoconf-archive
+    [ ] use to retrieve ax_pthread.m4 (gettext?)
+[ ] some way of patching development sources - version based? or just directory with "apply-to-any-revision" patches.
+[ ] dependencies like cloog
 
 A (slightly) ordered set of tasks for crosstool-NG. Written in a cryptic language; contact me if you want to help with any of these :)
 

packages/autoconf/package.desc

@@ -1,2 +1,3 @@
 repository='git git://git.sv.gnu.org/autoconf'
+bootstrap='autoreconf -vi'
 mirrors='$(CT_Mirrors GNU autoconf)'

packages/automake/package.desc

@@ -1,2 +1,3 @@
 repository='git https://git.savannah.gnu.org/git/automake.git'
+bootstrap='./bootstrap'
 mirrors='$(CT_Mirrors GNU automake)'

packages/libtool/package.desc

@@ -1,2 +1,3 @@
 repository='git git://git.savannah.gnu.org/libtool.git'
+bootstrap='./bootstrap'
 mirrors='$(CT_Mirrors GNU libtool)'

packages/ltrace/package.desc

@@ -1,2 +1,3 @@
 repository='git git://git.debian.org/git/collab-maint/ltrace.git'
+bootstrap='./autogen.sh'
 mirrors='http://ftp.debian.org/debian/pool/main/l/ltrace ftp:://ftp.debian.org/debian/pool/main/l/ltrace'

packages/m4/package.desc

@@ -1,2 +1,3 @@
 repository='git git://git.sv.gnu.org/m4'
+bootstrap='./bootstrap'
 mirrors='$(CT_Mirrors GNU m4)'

packages/make/package.desc

@@ -1,2 +1,3 @@
 repository='git https://git.savannah.gnu.org/git/make.git'
+bootstrap='autoreconf -i'
 mirrors='$(CT_Mirrors GNU make)'

packages/strace/package.desc

@@ -1,2 +1,3 @@
 repository='git https://git.code.sf.net/p/strace/code'
+bootstrap='./bootstrap'
 mirrors='http://downloads.sourceforge.net/project/strace/strace/${CT_STRACE_VERSION}'

scripts/functions

@@ -1629,6 +1629,7 @@ CT_GetVersion_git()
     if [ -z "${devel_revision}" ]; then
         local matches=`git ls-remote --exit-code "${devel_url}" --refs "${devel_branch}" \
             || echo "not found"`
+        local best using ref
 
         # Cannot test $?, setting a trap on ERR prevents bash from returning the
         # status code.
@@ -1636,9 +1637,22 @@ CT_GetVersion_git()
             CT_Abort "Failed to find git ref ${devel_branch} at ${devel_url}"
         fi
         if [ `echo "${matches}" | wc -l` -gt 1 ]; then
-            CT_DoLog WARN "Ambiguous ref ${devel_branch} at ${devel_url}, using first"
+            if echo "${matches}" | grep '[[:space:]]\(refs/heads/\)\?'"${devel_branch}\$" >/dev/null; then
+                # Try exact match, or prepended with "refs/heads". Some projects (e.g. binutils)
+                # have refs/original/refs/heads/master as well as refs/heads/master, and
+                # `git ls-remote refs/heads/master` prints both.
+                best=`echo "${matches}" | grep '[[:space:]]\(refs/heads/\)\?'"${devel_branch}\$"`
+                using="best match"
+            else
+                best=`echo "${matches}" | head -n1`
+                using="first"
+            fi
+            ref=`echo "${best}" | sed 's/.*[[:space:]]//'`
+            CT_DoLog WARN "Ambiguous ref ${devel_branch} at ${devel_url}, using ${using} (${ref})"
+        else
+            best="${matches}"
         fi
-        devel_revision=`echo "$matches" | head -n1 | cut -c1-8`
+        devel_revision=`echo "${best}" | cut -c1-8`
         CT_DoLog DEBUG "ref ${devel_branch} at ${devel_url} has cset of ${devel_revision}"
     fi
     basename="${pkg_name}-${devel_revision}"
@@ -1647,6 +1661,7 @@ CT_GetVersion_git()
 # Retrieve sources from Git.
 CT_Download_git()
 {
+    # Git does not allow making a shallow clone of a specific commit.
     CT_DoExecLog ALL git clone "${devel_url}" "${pkg_name}"
     CT_Pushd "${pkg_name}"
     CT_DoExecLog ALL git checkout "${devel_revision}" --