Wrapper around convert to avoid Inkscape use

See comments in the script

convert-wrapper.sh

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+#!/bin/sh
+
+# A wrapper around ImageMagick's `convert` so we can
+# prevent it from using Inkscape to convert SVG files
+# (which can pollute one's local filesystem with a fontcache;
+# as reported by Tim Dickson, who helps maintain the
+# Slackware version of the 'tuxpaint' package).
+#
+# Bill Kendrick <bill@newbreedsoftware.com>
+# with input from Mark Kim, TOYAMA Shin-ichi, and Tim Dickson.
+#
+# Last modified: 2023-06-17
+
+INPUT=`{
+  shift \`expr $# - 2\`
+  echo $1
+}`
+FILEEXT=`echo "$INPUT" | awk -F"." '{printf $NF}'`
+
+if [ x$FILEEXT = "xsvg" ]; then
+  # An SVG!
+
+  # Create a dummy 'inkscape' that exits in such a way
+  # that Imagemagick's `convert` will fallback to another
+  # SVG converter, thus avoiding invoking the real Inkscape.
+  echo "exit 1" > ./inkscape
+  
+  # Add the local directory to the beginning of this script's
+  # $PATH so `convert` finds the dummy script we just made.
+  export PATH="`pwd`":"${PATH}"
+  
+  # Now run `convert` in the usual way (and grab its exit status,
+  # so we don't catch `rm`'s)
+  convert $@
+  EXIT=$?
+  
+  # Clean up
+  rm ./inkscape
+else
+  # Not an SVG (so, a PNG or JPEG); just run `convert` as usual.
+  convert $@
+  EXIT=$?
+fi
+
+exit $EXIT
+