[Fix] nvm_err, nvm_err_with_colors: do not fail when stderr is closed

nvm.sh

@@ -33,12 +33,15 @@ nvm_cd() {
   \cd "$@"
 }
 
+# a caller that closed stderr, rather than redirecting it to /dev/null, makes
+# the `>&2` fail; zsh cannot report that, so it aborts the script, which only a
+# subshell contains, and `|| return 0` keeps the status from the caller
 nvm_err() {
-  >&2 nvm_echo "$@"
+  (>&2 nvm_echo "$@") || return 0
 }
 
 nvm_err_with_colors() {
-  >&2 nvm_echo_with_colors "$@"
+  (>&2 nvm_echo_with_colors "$@") || return 0
 }
 
 nvm_grep() {

test/fast/Unit tests/nvm_compare_checksum

@@ -54,4 +54,6 @@ EXPECTED_OUTPUT='Checksums matched!'
 [ "${CAPTURED_STDERR}" = "${EXPECTED_OUTPUT}" ] || die "expected >${EXPECTED_OUTPUT}<, got >${CAPTURED_STDERR}<"
 [ "${CAPTURED_EXIT_CODE}" = 0 ] || die "expected to exit with code 0, got ${CAPTURED_EXIT_CODE}"
 
+(set +x; nvm_compare_checksum ../../../nvm.sh checksum 2>&-) || die "with stderr closed, expected to exit with code 0, got $?"
+
 cleanup

test/fast/Unit tests/nvm_err

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+: nvm.sh
+\. ../../../nvm.sh
+
+\. ../../common.sh
+
+try_err nvm_err 'an error'
+EXPECTED_OUTPUT='an error'
+[ "${CAPTURED_STDERR}" = "${EXPECTED_OUTPUT}" ] || die "expected >${EXPECTED_OUTPUT}<, got >${CAPTURED_STDERR}<"
+[ "${CAPTURED_EXIT_CODE}" = 0 ] || die "expected to exit with code 0, got ${CAPTURED_EXIT_CODE}"
+
+try_err nvm_err_with_colors 'an error'
+EXPECTED_OUTPUT='an error'
+[ "${CAPTURED_STDERR}" = "${EXPECTED_OUTPUT}" ] || die "expected >${EXPECTED_OUTPUT}<, got >${CAPTURED_STDERR}<"
+[ "${CAPTURED_EXIT_CODE}" = 0 ] || die "expected to exit with code 0, got ${CAPTURED_EXIT_CODE}"
+
+nvm_err 'an error' 2>&- || die "nvm_err with stderr closed exited with code $?"
+nvm_err_with_colors 'an error' 2>&- || die "nvm_err_with_colors with stderr closed exited with code $?"