Update

.gitmodules

@@ -1,15 +1,20 @@
 [submodule "zep"]
 	path = zep
 	url = https://github.com/Rezonality/zep
+	branch = master
 [submodule "vcpkg"]
 	path = vcpkg
 	url = https://github.com/Microsoft/vcpkg.git
+	branch = master
 [submodule "libs/zing"]
 	path = libs/zing
 	url = https://github.com/Rezonality/zing
+	branch = main
 [submodule "libs/rccp"]
 	path = libs/rccp
 	url = https://github.com/RuntimeCompiledCPlusPlus/RuntimeCompiledCPlusPlus
+	branch = master
 [submodule "libs/nanovg_vulkan"]
 	path = libs/nanovg_vulkan
 	url = https://github.com/danilw/nanovg_vulkan.git
+	branch = master

clean-repo.sh

@@ -0,0 +1,31 @@
+git config -f .gitmodules --get-regexp '^submodule\..*\.path$' |
+    while read path_key path
+    do
+        url_key=$(echo $path_key | sed 's/\.path/.url/');
+        branch_key=$(echo $path_key | sed 's/\.path/.branch/');
+        # If the url_key doesn't yet exist then backup up the existing
+        # directory if necessary and add the submodule
+        if [ ! $(git config --get "$url_key") ]; then
+            if [ -d "$path" ] && [ ! $(git config --get "$url_key") ]; then
+                mv "$path" "$path""_backup_""$(date +'%Y%m%d%H%M%S')";
+            fi;
+            url=$(git config -f .gitmodules --get "$url_key");
+            # If a branch is specified then use that one, otherwise
+            # default to master
+            branch=$(git config -f .gitmodules --get "$branch_key");
+            if [ ! "$branch" ]; then branch="main"; fi;
+            git submodule add -f -b "$branch" "$url" "$path";
+        fi;
+    done;
+
+# In case the submodule exists in .git/config but the url is out of date
+
+git submodule sync;
+
+# Now actually pull all the modules. I used to use this...
+#
+# git submodule update --init --remote --force --recursive
+# ...but the submodules would check out in detached HEAD state and I 
+# didn't like that, so now I do this...
+
+git submodule foreach --recursive 'git checkout $(git config -f $toplevel/.gitmodules submodule.$name.branch || echo main)';