Fix AnsiLogObserver sticky messages duplicated when lines wrap [ci fast] (#6852)

Account for terminal line wrapping when counting visual lines in the
ANSI progress renderer. Previously only explicit newlines were counted,
causing cursorUp to undershoot when messages exceeded terminal width.

Signed-off-by: Paolo Di Tommaso <paolo.ditommaso@gmail.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: pditommaso

modules/nextflow/src/main/groovy/nextflow/trace/AnsiLogObserver.groovy

@@ -345,12 +345,36 @@ class AnsiLogObserver implements TraceObserverV2 {
     protected int printAndCountLines(String str) {
         if( str ) {
             printAnsiLines(str)
-            return str.count(NEWLINE)
+            return countVisualLines(str)
         }
         else
             return 0
     }
 
+    /**
+     * Count the number of visual lines the string occupies on the terminal,
+     * accounting for lines that wrap when they exceed the terminal width.
+     */
+    protected int countVisualLines(String str) {
+        final lines = str.split(NEWLINE, -1)
+        int count = 0
+        // the last element after split is always empty (trailing newline), skip it
+        for( int i=0; i<lines.length-1; i++ ) {
+            final visualLen = stripAnsi(lines[i]).length()
+            // each line takes at least 1 visual line, plus extra lines for wrapping
+            count += visualLen > 0 && cols > 0 ? Math.ceil((double)visualLen / cols).intValue() : 1
+        }
+        return count
+    }
+
+    /**
+     * Strip ANSI escape codes and OSC hyperlinks from a string
+     * to determine its visual display width.
+     */
+    protected static String stripAnsi(String str) {
+        return ANSI_ESCAPE.matcher(str).replaceAll('')
+    }
+
     protected void renderSummary(WorkflowStats stats) {
         final delta = endTimestamp-startTimestamp
         if( enableSummary == false )
@@ -415,6 +439,7 @@ class AnsiLogObserver implements TraceObserverV2 {
 
     private final static Pattern TAG_REGEX = ~/ \((.+)\)( *)$/
     private final static Pattern LBL_REPLACE = ~/ \(.+\) *$/
+    private final static Pattern ANSI_ESCAPE = ~/\033\[[0-9;]*[a-zA-Z]|\033][^\007]*\007/
 
     // OSC 8 hyperlink escape sequences (using BEL as String Terminator)
     private final static String HYPERLINK_START = '\033]8;;'

modules/nextflow/src/test/groovy/nextflow/trace/AnsiLogObserverTest.groovy

@@ -147,6 +147,36 @@ class AnsiLogObserverTest extends Specification {
         's3://bucket/work/4e/486876abc'  | 's3://bucket/work/4e/486876abc'
     }
 
+    def 'should strip ansi escape codes' () {
+        expect:
+        AnsiLogObserver.stripAnsi('hello') == 'hello'
+        AnsiLogObserver.stripAnsi('\033[32mgreen\033[0m') == 'green'
+        AnsiLogObserver.stripAnsi('\033[1;31mbold red\033[0m') == 'bold red'
+        AnsiLogObserver.stripAnsi('\033]8;;http://example.com\007link\033]8;;\007') == 'link'
+        AnsiLogObserver.stripAnsi('\033[2m[\033[0m\033[34mab/123456\033[0m\033[2m] \033[0mfoo') == '[ab/123456] foo'
+    }
+
+    @Unroll
+    def 'should count visual lines with wrapping' () {
+        given:
+        def observer = new AnsiLogObserver()
+        observer.@cols = COLS
+
+        expect:
+        observer.countVisualLines(INPUT) == EXPECTED
+
+        where:
+        COLS | INPUT                        | EXPECTED
+        80   | 'short line\n'               | 1
+        80   | 'line1\nline2\n'             | 2
+        80   | 'a' * 80 + '\n'              | 1       // exactly fits, no wrap
+        80   | 'a' * 81 + '\n'              | 2       // wraps to 2 lines
+        80   | 'a' * 160 + '\n'             | 2       // exactly 2 lines
+        80   | 'a' * 161 + '\n'             | 3       // wraps to 3 lines
+        40   | 'a' * 100 + '\n'             | 3       // 100 chars in 40-col terminal
+        80   | 'short\n' + 'a' * 200 + '\n'| 4       // 1 + 3 lines
+    }
+
     def 'should not render hyperlink when cleanup is enabled' () {
         given:
         def session = Mock(Session) { getConfig() >> [cleanup: true] }