Keep blank REPL lines when the prompt has no trailing space

sphinx_copybutton/_static/copybutton_funcs.js

@@ -42,8 +42,15 @@ export function formatCopyText(textContent, copybuttonPromptText, isRegexp = fal
     const lineGotPrompt = [];
     for (const line of textContent.split('\n')) {
         match = line.match(regexp)
+        if (!match) {
+            // Blank REPL lines are often ">>>" without the trailing space in ">>> ".
+            const padded = (line + ' ').match(regexp)
+            if (padded && padded[2] === '') {
+                match = padded
+            }
+        }
         if (match || gotLineCont || gotHereDoc) {
-            promptFound = regexp.test(line)
+            promptFound = !!match
             lineGotPrompt.push(promptFound)
             if (removePrompts && promptFound) {
                 outputLines.push(match[2])

sphinx_copybutton/_static/test.js

@@ -32,6 +32,31 @@ output
 		removePrompts: true,
 		expected: '\nfirst\nsecond'
 	},
+	{
+		description: 'with non-regexp python prompt and blank REPL line',
+		text: `
+>>> first
+>>>
+>>> second`,
+		prompt: '>>> ',
+		isRegexp: false,
+		onlyCopyPromptLines: true,
+		removePrompts: true,
+		expected: '\nfirst\n\nsecond'
+	},
+	{
+		description: 'with regexp python prompt and blank REPL line',
+		text: `
+>>> first
+>>>
+>>> second`,
+		prompt: '>>> ',
+		isRegexp: true,
+		onlyCopyPromptLines: true,
+		removePrompts: true,
+		copyEmptyLines: true,
+		expected: '\nfirst\n\nsecond'
+	},
 	{
 		description: 'with non-regexp console prompt',
 		text: `