A script I once wrote to vendor NSS into gecko

nss-vendor.sh

@@ -0,0 +1,88 @@
+#!/bin/bash
+# Vendor a mercurial tag into the tree.
+
+set -e
+
+declare -A sources=( \
+    [nss]=https://hg.mozilla.org/projects/nss \
+    [nspr]=https://hg.mozilla.org/projects/nspr \
+    )
+declare -A destinations=( \
+    [nss]=security/nss \
+    [nspr]=nsprpub \
+    )
+declare -A depfiles=( \
+    [nss]=coreconf/coreconf.dep \
+    [nspr]=config/prdepend.h \
+    )
+
+root="$(hg root 2>/dev/null || true)"
+cmd=hg
+if [[ -z "$root" ]]; then
+    cmd=git
+    root="$(git rev-parse --show-toplevel 2>/dev/null || true)"
+fi
+[[ -n "$root" ]] || ! echo "Unable to find repository root and type." 1>&2
+
+is_clean() {
+    [[ "$cmd" == "hg" ]] && [[ -z "$(hg status -mardu)" ]]
+    [[ "$cmd" == "git" ]] && [[ -z "$(git status --porcelain)" ]]
+}
+
+is_clean || ! echo "Unmodified files in repository." 1>&2
+
+usage() {
+    echo "Usage: $0 <nss|nspr> <tag> [source]"
+    return 2
+}
+
+[[ $# -ge 2 ]] || usage
+
+project="${1,,*}"
+tag="$2"
+source="${3:-${sources[$project]}}"
+[[ -n "$source" ]] || \
+    ! echo "Unable to determine source for $project."
+[[ -n "${destinations[$project]}" ]] || \
+    ! echo "Unable to determine destination for $project."
+dest="$root/${destinations[$project]}"
+depfile="${depfiles[$project]}"
+
+log() {
+    echo "run: $@"
+    "$@"
+}
+
+# If set, use $depfile to tell the gecko build that NSS has changed.
+# We do that by alternating between a blank line and the end and not.
+if [[ -n "$depfile" ]]; then
+    depfile="$dest/$depfile"
+    lastline="$(tail -1 "$depfile" 2>/dev/null)"
+fi
+
+# Remove the old, replace with the new.
+log rm -rf "$dest"
+log hg clone -r "$tag" "$source" "$dest"
+for remove in .hg .hgignore .hgtags; do
+    log rm -rf "$dest/$remove"
+done
+
+# Update the metadata files.
+echo "Write '$tag' to TAG-INFO"
+echo "$tag" > "$dest/TAG-INFO"
+if [[ -n "$depfile" ]]; then
+    if [[ -n "$lastline" ]]; then
+        echo "Adding blank line to $depfile"
+        echo >> "$depfile"
+    else 
+        [[ -n "$(tail -1 "$depfile")" ]] || \
+            ! echo "Source for $depfile has a blank line."
+    fi
+else
+    echo "Skipping dependency file update."
+fi
+
+# Make a commit with the changes.
+log "$cmd" add "$dest"
+comment="Bug ${BUG:-XXXXXXX} - Update ${project^^*} to $tag, UPGRADE_${project^^*}_RELEASE, r=me"
+log "$cmd" commit -m "$comment" "$dest"