attempt to regen source maps in git-hooks

if css changes

git-hooks/README.md

@@ -3,7 +3,7 b' git hooks for IPython'
 add these to your `.git/hooks`
 
 For now, we just have `post-checkout` and `post-merge`,
-both of which just update submodules,
+both of which update submodules and attempt to rebuild css sourcemaps,
 so make sure that you have a fully synced repo whenever you checkout or pull.
 
 To use these hooks, run `./install-hooks.sh`. 

git-hooks/post-checkout

@@ -2,3 +2,16 b''
 
 git submodule init
 git submodule update
+
+PREVIOUS_HEAD=$1
+# if style changed (and less/fabric available), rebuild sourcemaps
+if [[
+  ! -z "$(git diff $PREVIOUS_HEAD IPython/html/static/style/ipython.min.css)"
+  && ! -z "$(git diff $PREVIOUS_HEAD IPython/html/static/style/style.min.css)"
+  && ! -z $(which 2>/dev/null lessc)
+  && ! -z $(which 2>/dev/null fab)
+]]; then
+  echo "rebuilding sourcemaps"
+  cd IPython/html
+  fab css
+fi

git-hooks/post-merge

@@ -2,3 +2,16 b''
 
 git submodule init
 git submodule update
+
+PREVIOUS_HEAD=$1
+# if style changed (and less/fabric available), rebuild sourcemaps
+if [[
+  ! -z "$(git diff $PREVIOUS_HEAD IPython/html/static/style/ipython.min.css)"
+  && ! -z "$(git diff $PREVIOUS_HEAD IPython/html/static/style/style.min.css)"
+  && ! -z $(which 2>/dev/null lessc)
+  && ! -z $(which 2>/dev/null fab)
+]]; then
+  echo "rebuilding sourcemaps"
+  cd IPython/html
+  fab css
+fi