symfony-console-completion string and escaping parsing

strings-and-escaping.patch

diff --git a/src/CompletionContext.php b/src/CompletionContext.php
index 6029253..4316801 100644
--- a/src/CompletionContext.php
+++ b/src/CompletionContext.php
@@ -198,20 +198,13 @@ class CompletionContext
         $this->wordIndex = null;
         $cursor = 0;
 
-        $breaks = preg_quote($this->wordBreaks);
+        $matches = $this->splitOnBreaks($this->commandLine, $this->wordBreaks);
 
-        if (!preg_match_all("/([^$breaks]*)([$breaks]*)/", $this->commandLine, $matches)) {
-            return;
-        }
-
-        // Groups:
-        // 1: Word
-        // 2: Break characters
-        foreach ($matches[0] as $index => $wholeMatch) {
+        foreach ($matches as $index => $match) {
             // Determine which word the cursor is in
-            $cursor += strlen($wholeMatch);
-            $word = $matches[1][$index];
-            $breaks = $matches[2][$index];
+            $word = $match['word'];
+            $breaks = $match['break'];
+            $cursor += strlen($word) + strlen($breaks);
 
             if ($this->wordIndex === null && $cursor >= $this->charIndex) {
                 $this->wordIndex = $index;
@@ -246,6 +239,96 @@ class CompletionContext
     }
 
     /**
+     * Split a string into words on break characters, accounting for strings and escaped spaces
+     *
+     * Returns a collection of ['word' => string, 'break' => string] groups for each word,
+     * where "break" is the non-word characters between this word and then following one.
+     *
+     * @param string $string
+     * @param string $breaks
+     * @param string[] $wordGroupers
+     * @return array
+     */
+    protected function splitOnBreaks($string, $breaks, $wordGroupers = ['\'', '"'])
+    {
+        $matches = [];
+
+        $word = '';
+        $break = '';
+
+        $currentGroup = null;
+        $escaping = false;
+        $inBreakSpace = false;
+
+        for ($pos = 0, $length = strlen($string); $pos < $length; $pos++) {
+            $char = $string[$pos];
+            $treatAsWord = false;
+
+            // If we're escaping, we don't care what this character is - add it to the word
+            if ($escaping) {
+                $escaping = false;
+                $treatAsWord = true;
+            }
+
+            // If a backslash is encountered, ignore any special function of the following character
+            else if ($char === '\\' && !$escaping) {
+                $escaping = true;
+                $treatAsWord = true;
+            }
+
+            // Check for the start or end of a group
+            // We can only be inside one group at a time
+            else {
+                foreach ($wordGroupers as $groupChar) {
+                    if ($char === $groupChar) {
+                        // If we encouter the character that opened the current group, close the group
+                        if ($currentGroup === $groupChar) {
+                            $currentGroup = null;
+                            break;
+                        }
+
+                        // If we're not in a group yet, use this character as the group
+                        if (!$currentGroup) {
+                            $currentGroup = $groupChar;
+                            break;
+                        }
+                    }
+                }
+            }
+
+            // If this is not a break character, add it to the word, otherwise add to the break space
+            // Being inside a group counts break characters as word characters
+            if ($treatAsWord || $currentGroup !== null || strpos($breaks, $char) === false) {
+
+                // If the previous character was a break, this is a new word
+                if ($inBreakSpace) {
+                    $matches[] = [
+                        'word' => $word,
+                        'break' => $break
+                    ];
+
+                    $word = '';
+                    $break = '';
+                    $inBreakSpace = false;
+                }
+
+                $word .= $char;
+            } else {
+                $inBreakSpace = true;
+                $break .= $char;
+            }
+        }
+
+        // Append the last word
+        $matches[] = [
+            'word' => $word,
+            'break' => $break
+        ];
+
+        return $matches;
+    }
+
+    /**
      * Reset the computed words so that $this->splitWords is forced to run again
      */
     protected function reset()