Deal with several ShellCheck warnings

Work around, obey, or disable.

dotfiles/bash/main.bashrc

@@ -1,7 +1,7 @@
 #!/bin/bash
-#shellcheck disable=SC1091
 
 ## hack to workaround Fedora/Red Hat bug 878428
+#shellcheck disable=SC1091
 test -f /usr/share/git-core/contrib/completion/git-prompt.sh \
  && . /usr/share/git-core/contrib/completion/git-prompt.sh
 
@@ -147,7 +147,7 @@ gitcd() {
     #
     # Deep in git repo, cd to the git root
     #
-    cd "$(git rev-parse --show-toplevel)"
+    cd "$(git rev-parse --show-toplevel)" || return 1
 }
 
 clsz() {
@@ -171,7 +171,7 @@ strip_colors() {
     #
     # Stolen from http://unix.stackexchange.com/a/4533/9365
     #
-    sed -r "s/\x1B\[([0-9]{1,2}(;[0-9]{1,2})?)?[m|K]//g"
+    sed -r 's/\x1B\[([0-9]{1,2}(;[0-9]{1,2})?)?[m|K]//g'
 }
 
 vims() {
@@ -200,6 +200,7 @@ vims() {
     # disaster.
     #
     local swap="$HOME/.local/share/vim/swap"
+    #shellcheck disable=SC1117
     find "$swap" -type f -print0 \
       | xargs -0 -r stat -c "%y %n" \
       | sed "
@@ -346,7 +347,8 @@ xod() {
     #     rm useful_name.txt
     #
     local name="${1:-clipboard_dump.txt}"
-    local tmp=$(mktemp -d -t "xod.XXXXXXXX")
+    local tmp
+    tmp=$(mktemp -d -t "xod.XXXXXXXX")
     xclip -o > "$tmp/$name"
     echo "$tmp/$name"
 }
@@ -356,7 +358,8 @@ xood() {
     # Just like xod() but using xoo (i.e. 'clipboard' clipboard)
     #
     local name="${1:-clipboard_dump.txt}"
-    local tmp=$(mktemp -d -t "xood.XXXXXXXX")
+    local tmp
+    tmp=$(mktemp -d -t "xood.XXXXXXXX")
     xclip -selection clipboard -o > "$tmp/$name"
     echo "$tmp/$name"
 }
@@ -502,9 +505,13 @@ export LESS=' -R '
 export PRETTY=color
 export PRETTY_DEBUG_EXCLUDE=inigrep
 
-GIT_PS1_SHOWDIRTYSTATE=true
-GIT_PS1_SHOWUNTRACKEDFILES=true
-GIT_DISABLED_COMMANDS="$HOME/.gittum/disabled-commands"
+#shellcheck disable=SC2034
+{
+    GIT_PS1_SHOWDIRTYSTATE=true
+    GIT_PS1_SHOWUNTRACKEDFILES=true
+    __SATURNIN_COMPLETE_DEBUG=true
+    GIT_DISABLED_COMMANDS="$HOME/.gittum/disabled-commands"
+}
 export GIT_PAGER='less -S'
 
 # disable mounting things like SFTP to ~/.gvfs when accessed