[#630] Only load org.fusesource.jansi.AnsiConsole when running on W…

…indows to avoid JVM crashes on non-Windows platforms.

RELEASE-NOTES.md

@@ -1,5 +1,39 @@
 # picocli Release Notes
 
+# <a name="3.9.5"></a> Picocli 3.9.5
+The picocli community is pleased to announce picocli 3.9.5.
+
+This release contains a critical workaround to protect against JVM crashes when running on RedHat Linux 3.10.0-327.44.2.el7.x86_64.
+
+Picocli 3.9.0 introduced a change in the heuristics for emitting ANSI escape characters. As part of this change, picocli may load the `org.fusesource.jansi.AnsiConsole` class from the JAnsi library when not running on Windows. This may crash the JVM (see [fusesource/jansi-native#17](https://github.com/fusesource/jansi-native/issues/17)).
+
+The workaround in this release is to only load the `AnsiConsole` class when running on Windows.
+
+Users using 3.9.0 and higher are strongly recommended to upgrade to 3.9.5 or later.
+
+
+This is the fiftieth public release.
+Picocli follows [semantic versioning](http://semver.org/).
+
+## <a name="3.9.5"></a> Table of Contents
+* [New and noteworthy](#3.9.5-new)
+* [Fixed issues](#3.9.5-fixes)
+* [Deprecations](#3.9.5-deprecated)
+* [Potential breaking changes](#3.9.5-breaking-changes)
+
+## <a name="3.9.5-new"></a> New and Noteworthy
+
+
+## <a name="3.9.5-fixes"></a> Fixed issues
+- [#630] Avoid loading `org.fusesource.jansi.AnsiConsole` when not running on Windows to avoid JVM crashes on non-Windows platforms.
+
+## <a name="3.9.5-deprecated"></a> Deprecations
+No features were deprecated in this release.
+
+## <a name="3.9.5-breaking-changes"></a> Potential breaking changes
+This release has no breaking changes.
+
+
 # <a name="3.9.4"></a> Picocli 3.9.4
 The picocli community is pleased to announce picocli 3.9.4.
 

docs/index.adoc

@@ -1891,7 +1891,7 @@ Below is the exact sequence of steps picocli uses to determine whether or not to
 . If `Ansi.ON` or `Ansi.OFF` is <<Forcing ANSI On/Off,explicitly specified>>, either via system property `picocli.ansi` or programmatically, this value is used.
 . ANSI is disabled when environment variable https://no-color.org/[`NO_COLOR`] is defined (regardless of its value).
 . ANSI is enabled when environment variable https://bixense.com/clicolors/[`CLICOLOR_FORCE`] is defined and has any value other than `0` (zero).
-. ANSI is enabled when JAnsi Console is https://github.com/fusesource/jansi[installed].
+. ANSI is enabled when system property `os.name` starts with `"Windows"` and JAnsi Console is https://github.com/fusesource/jansi[installed].
 . ANSI is disabled when environment variable https://bixense.com/clicolors/[`CLICOLOR == 0`].
 . ANSI is disabled when environment variable https://conemu.github.io/en/AnsiEscapeCodes.html#Environment_variable[`ConEmuANSI == OFF`].
 . ANSI is disabled when Picocli https://stackoverflow.com/questions/1403772/how-can-i-check-if-a-java-programs-input-output-streams-are-connected-to-a-term[_guesses_] the program's output stream is not connected to a terminal: when `System.console()` returns `null`. This check is omitted if picocli _guesses_ the program is running in a Windows https://www.cygwin.com/[Cygwin] or http://www.mingw.org/wiki/MSYS[MSYS] environment: when system property `os.name` starts with `"Windows"` and either environment variable `TERM` starts with `xterm` or environment variable `OSTYPE` is defined.

src/main/java/picocli/CommandLine.java

@@ -10079,11 +10079,11 @@ static boolean calcTTY() {
             static boolean isPseudoTTY() { return isWindows() && (isXterm() || hasOsType()); }
 
             static boolean ansiPossible() {
-                if (forceDisabled())              { return false; }
-                if (forceEnabled())               { return true; }
-                if (isJansiConsoleInstalled())    { return true; }
-                if (hintDisabled())               { return false; }
-                if (!isTTY() && !isPseudoTTY())   { return false; }
+                if (forceDisabled())                          { return false; }
+                if (forceEnabled())                           { return true; }
+                if (isWindows() && isJansiConsoleInstalled()) { return true; } // #630 JVM crash loading jansi.AnsiConsole on Linux
+                if (hintDisabled())                           { return false; }
+                if (!isTTY() && !isPseudoTTY())               { return false; }
                 return hintEnabled() || !isWindows() || isXterm() || hasOsType();
             }
             static boolean isJansiConsoleInstalled() {