Optimize parch header parser

Author: kpdecker

src/patch/parse.js

@@ -53,16 +53,16 @@ export function parsePatch(uniDiff, options = {}) {
   // Parses the --- and +++ headers, if none are found, no lines
   // are consumed.
   function parseFileHeader(index) {
-    const headerPattern = /^(---|\+\+\+)\s+([\S ]*)(?:\t(.*?)\s*)?$/;
-    const fileHeader = headerPattern.exec(diffstr[i]);
+    const fileHeader = (/^(---|\+\+\+)\s+(.*)$/).exec(diffstr[i]);
     if (fileHeader) {
       let keyPrefix = fileHeader[1] === '---' ? 'old' : 'new';
-      let fileName = fileHeader[2].replace(/\\\\/g, '\\');
+      const data = fileHeader[2].split('\t', 2);
+      let fileName = data[0].replace(/\\\\/g, '\\');
       if (/^".*"$/.test(fileName)) {
         fileName = fileName.substr(1, fileName.length - 2);
       }
       index[keyPrefix + 'FileName'] = fileName;
-      index[keyPrefix + 'Header'] = fileHeader[3];
+      index[keyPrefix + 'Header'] = (data[1] || '').trim();
 
       i++;
     }