[MWRAPPER-139] Remove trailing whitespace from fields in maven-wrapper.properties (#139)

This prevents issues due to confusion between CRLF and LF when
running in more exotic locations such as MINGW on Windows but
using ./mvnw rather than ./mvnw.cmd. A prime example of where
this is an issue would be on windows-latest GitHub Actions
runners.

Fixes MWRAPPER-139, MWRAPPER-137.

---

https://issues.apache.org/jira/browse/MWRAPPER-139
https://issues.apache.org/jira/browse/MWRAPPER-137
https://issues.apache.org/jira/browse/MWRAPPER-136

Author: ascopes

maven-wrapper-distribution/src/resources/only-mvnw

@@ -97,11 +97,19 @@ die() {
   exit 1
 }
 
+trim() {
+  # MWRAPPER-139:
+  #   Trims trailing and leading whitespace, carriage returns, tabs, and linefeeds.
+  #   Needed for removing poorly interpreted newline sequences when running in more
+  #   exotic environments such as mingw bash on Windows.
+  printf "%s" "${1}" | tr -d '[:space:]'
+}
+
 # parse distributionUrl and optional distributionSha256Sum, requires .mvn/wrapper/maven-wrapper.properties
 while IFS="=" read -r key value; do
   case "${key-}" in
-  distributionUrl) distributionUrl="${value-}" ;;
-  distributionSha256Sum) distributionSha256Sum="${value-}" ;;
+  distributionUrl) distributionUrl=$(trim "${value-}") ;;
+  distributionSha256Sum) distributionSha256Sum=$(trim "${value-}") ;;
   esac
 done <"${0%/*}/.mvn/wrapper/maven-wrapper.properties"
 [ -n "${distributionUrl-}" ] || die "cannot read distributionUrl property in ${0%/*}/.mvn/wrapper/maven-wrapper.properties"