Make wrapper script more robust... more robustly (#473)

* Make wrapper script more robust... more robustly

This makes a setup possible in which a symlink points to the file
(e.g. /usr/local/bin/elixir-ls -> /opt/elixir-ls/language_server.sh).

It's a rehash of a previous commit that was reverted since it broke
setups where the language server was installed in a path containing
spaces (e.g. /opt/Elixir Language Server/). This variant takes that
possibility into account.

* Avoid undefined behaviour in launch.sh

I'm not really sure what could lead this to happen. Maybe some weird
directory permissions with the read bit on and the exec bit off...

Still good to be careful though.

Co-authored-by: Łukasz Samson <[email protected]>

Co-authored-by: Joshua Trees <[email protected]>
Co-authored-by: Łukasz Samson <[email protected]>

Author: jtrees

apps/elixir_ls_utils/priv/debugger.sh

@@ -1,8 +1,18 @@
 #!/bin/sh
 # Launches the debugger. This script must be in the same directory as the compiled .ez archives.
 
+readlink_f () {
+  cd "$(dirname "$1")" > /dev/null || exit 1
+  filename="$(basename "$1")"
+  if [ -h "$filename" ]; then
+    readlink_f "$(readlink "$filename")"
+  else
+    echo "$(pwd -P)/$filename"
+  fi
+}
+
 if [ -z "${ELS_INSTALL_PREFIX}" ]; then
-  dir=$(dirname "$0")
+  dir="$(dirname "$(readlink_f "$0")")"
 else
   dir=${ELS_INSTALL_PREFIX}
 fi

apps/elixir_ls_utils/priv/language_server.sh

@@ -1,8 +1,18 @@
 #!/bin/sh
 # Launches the language server. This script must be in the same directory as the compiled .ez archives.
 
+readlink_f () {
+  cd "$(dirname "$1")" > /dev/null || exit 1
+  filename="$(basename "$1")"
+  if [ -h "$filename" ]; then
+    readlink_f "$(readlink "$filename")"
+  else
+    echo "$(pwd -P)/$filename"
+  fi
+}
+
 if [ -z "${ELS_INSTALL_PREFIX}" ]; then
-  dir=$(dirname "$0")
+  dir="$(dirname "$(readlink_f "$0")")"
 else
   dir=${ELS_INSTALL_PREFIX}
 fi

apps/elixir_ls_utils/priv/launch.sh

@@ -52,7 +52,7 @@ fi
 # include the local .ez files, and then do what we were asked to do.
 
 readlink_f () {
-  cd "$(dirname "$1")" > /dev/null
+  cd "$(dirname "$1")" > /dev/null || exit 1
   filename="$(basename "$1")"
   if [ -h "$filename" ]; then
     readlink_f "$(readlink "$filename")"