Fix char counting for multibyte UTF-8 inputs, bump Perl requirement t…

…o 5.8.7

Addresses #69 and #65.

This UTF-8 handling approach is based on Debian's UTF-8 handling patch for cowsay 3.03 at https://sources.debian.org/patches/cowsay/3.03%2Bdfsg2-8/utf8_width, discussed at https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=254557. It has been in place on Debian since 2010, so I think we can consider it reasonably well tested and supported.

CHANGELOG.md

@@ -3,7 +3,10 @@ Cowsay Changelog
 
 ## 3.9.0 (unreleased)
 
-(nothing here yet)
+### Changes
+
+- Require Perl 5.8.7 or later.
+- Fix character counts for multibyte UTF-8 inputs. ([#69](https://github.com/cowsay-org/cowsay/issues/69))
 
 ## 3.8.5 (unreleased)
 

README.md

@@ -54,7 +54,7 @@ As of 2016, Monroe was no longer interested in maintaining Cowsay, and posted a
 
 ## Requirements
 
-Cowsay requires Perl 5.005_03 or later. Because all our development and testing is done with the Perl from recent OS distributions, it may well require a version newer than 5.005_03, but I'm not sure exactly which.
+Cowsay requires Perl 5.8.7 or later.
 
 ## Other cow collections
 

bin/cowsay

@@ -29,6 +29,25 @@ $Text::Wrap::initial_tab = 8;
 $Text::Wrap::subsequent_tab = 8;
 $Text::Wrap::tabstop = 8;
 
+sub enable_utf8_input() {
+    # Enable UTF-8 inputs on stdin/out/err if running in a UTF-8 locale.
+    # This fixes character-count problems with multibyte UTF-8 characters. (But
+    # it doesn't handle "wide" characters that should be *displayed* taking up
+    # multiple character spaces; that's a different issue.)
+    # This is done in the code here instead of relying on `perl -C` options 
+    # (e.g. in the shebang line) so that it still works when this program is
+    # called with plain `perl cowsay`.
+    if (${^UTF8LOCALE}) {
+        require Encode;
+        binmode STDIN, ':utf8';
+        binmode STDOUT, ':utf8';
+        binmode STDERR, ':utf8';
+        eval { $_ = Encode::decode_utf8($_,1) } for @ARGV;
+    }
+}
+
+&enable_utf8_input;
+
 %opts = (
     'e'         =>      'oo',
     'f'         =>      'default.cow',

doc-project/Release Checklist.md

@@ -53,7 +53,7 @@ See the "Developer Notes.md" doc for more details. (Well, as soon as I get to wr
 Dependencies and tools needed:
 
 1. Perl
-    1. Use version 5.005_03 or later, but hopefully not too new (for compatibility). As of 2024-11, I'm testing against Perl 5.40. Really probably should be using whatever version is in the oldest in-support releases of Debian/Ubuntu and Fedora.
+    1. Use version 5.8.7 or later, but preferably not too new (for compatibility). As of 2024-11, I'm testing against Perl 5.40. Really probably should be using whatever version is in the oldest in-support releases of Debian/Ubuntu and Fedora.
     2. Ideally, also test against the current Perl from Mac Homebrew.
 2. Asciidoctor
     1. Version 2.0.x or later.