Fixed two issues: handle spaces in paths, and don't copy assets.external into .lowres tree

chertex.sh

@@ -144,12 +144,15 @@ if [ $# -eq 1 ]; then
             # if $asset contains a space, the second element should be considered a local target folder for the copy operation
             # https://www.tutorialkart.com/bash-shell-scripting/bash-split-string/
             # https://stackoverflow.com/a/30212526
-            IFS=' ' # reset IFS
+            # Using space as separator was not working if the path contains spaces
+            # (I tried surrounding each path with "" or escaping each space with backslash, did not help)
+            # Rather than rewriting this part, I'll change to an IFS char that's unlikely to clash with any path specification. This way, spaces in paths should not need any changes.
+            IFS='>' # reset IFS
             # asset is read into an array as tokens separated by IFS
             read -ra asset_array <<< "$asset"
             # sanity check for array length
             if [ ${#asset_array[@]} -gt 2 ]; then
-               echo "<thesis> Cannot handle more than one space per line"
+               echo "<thesis> Cannot handle more than one $IFS character per line"
                echo "<cheRTeX> Terminating..."
                simpledelay.sh 2
                exit 1
@@ -190,14 +193,15 @@ if [ $# -eq 1 ]; then
       if [ ! -f "$photoslastrun" ]; then
          # if, for some reason, the lastrun file does not exist
          # copy over everything and then create the file 
-         rsync -av "$path_thesis/assets/photos/" "$path_thesis/assets/photos/.lowres/" --exclude ".lowres/"
+         # (except for the .lowres tree itself, and any assets.external files)
+         rsync -av "$path_thesis/assets/photos/" "$path_thesis/assets/photos/.lowres/" --exclude ".lowres/" --exclude "assets.external"
          touch "$photoslastrun"
       fi
       # Detect new photos and copy them into .lowres tree
       # https://stackoverflow.com/questions/9612090/how-to-loop-through-file-names-returned-by-find
       # https://stackoverflow.com/questions/5241625/find-and-copy-files
       cd "$path_thesis/assets/photos"
-      find . -type f -cnewer $photoslastrun ! -path "./.lowres/*" -print -exec cp --parents "{}" .lowres \;
+      find . -type f -cnewer $photoslastrun ! -path "./.lowres/*" ! -name "*.external" -print -exec cp --parents "{}" .lowres \;
       # revert the effects of cd above. Redirect to null suppresses the output.
       cd - >/dev/null
       # Convert all non-JPG images (except for PDF, SVG, and other non-images) to JPG