Fixes #1 Support blame on files outside repo

Replaces blame regex parsing with more robust parser (also use s--incremental instead of --porcelain)
Stops throwing on git blame errors (too many are common)
Fixes issues with Diff with Previous command
Fixes issues with blame explorer code lens -- with previous commits
Fixes issues with compact blame annotations -- skips blank lines

src/git/git.ts

@@ -0,0 +1,90 @@
+'use strict';
+import * as fs from 'fs';
+import * as path from 'path';
+import * as tmp from 'tmp';
+import {spawnPromise} from 'spawn-rx';
+
+export * from './gitEnrichment';
+//export * from './enrichers/blameRegExpEnricher';
+export * from './enrichers/blameParserEnricher';
+
+function gitCommand(cwd: string,  ...args) {
+    return spawnPromise('git', args, { cwd: cwd })
+        .then(s => {
+            console.log('[GitLens]', 'git', ...args);
+            return s;
+        })
+        .catch(ex => {
+            const msg = ex && ex.toString();
+            if (msg && (msg.includes('is outside repository') || msg.includes('no such path'))) {
+                console.warn('[GitLens]', 'git', ...args, msg && msg.replace(/\r?\n|\r/g, ' '));
+            } else {
+                console.error('[GitLens]', 'git', ...args, msg && msg.replace(/\r?\n|\r/g, ' '));
+            }
+            throw ex;
+        });
+}
+
+export type GitBlameFormat = '--incremental' | '--line-porcelain' | '--porcelain';
+export const GitBlameFormat = {
+    incremental: '--incremental' as GitBlameFormat,
+    linePorcelain: '--line-porcelain' as GitBlameFormat,
+    porcelain: '--porcelain' as GitBlameFormat
+}
+
+export default class Git {
+    static normalizePath(fileName: string, repoPath?: string) {
+        return fileName.replace(/\\/g, '/');
+    }
+
+    static splitPath(fileName: string) {
+        // if (!path.isAbsolute(fileName)) {
+        //     console.error('[GitLens]', `Git.splitPath(${fileName}) is not an absolute path!`);
+        //     debugger;
+        // }
+        return [path.basename(fileName).replace(/\\/g, '/'), path.dirname(fileName).replace(/\\/g, '/')];
+    }
+
+    static repoPath(cwd: string) {
+        return gitCommand(cwd, 'rev-parse', '--show-toplevel').then(data => data.replace(/\r?\n|\r/g, '').replace(/\\/g, '/'));
+    }
+
+    static blame(format: GitBlameFormat, fileName: string, sha?: string) {
+        const [file, root] = Git.splitPath(Git.normalizePath(fileName));
+
+        if (sha) {
+            return gitCommand(root, 'blame', format, '--root', `${sha}^`, '--', file);
+        }
+        return gitCommand(root, 'blame', format, '--root', '--', file);
+    }
+
+    static getVersionedFile(fileName: string, sha: string) {
+        return new Promise<string>((resolve, reject) => {
+            Git.getVersionedFileText(fileName, sha).then(data => {
+                const ext = path.extname(fileName);
+                tmp.file({ prefix: `${path.basename(fileName, ext)}-${sha}_`, postfix: ext }, (err, destination, fd, cleanupCallback) => {
+                    if (err) {
+                        reject(err);
+                        return;
+                    }
+
+                    //console.log(`getVersionedFile(${fileName}, ${sha}); destination=${destination}`);
+                    fs.appendFile(destination, data, err => {
+                        if (err) {
+                            reject(err);
+                            return;
+                        }
+                        resolve(destination);
+                    });
+                });
+            });
+        });
+    }
+
+    static getVersionedFileText(fileName: string, sha: string) {
+        const [file, root] = Git.splitPath(Git.normalizePath(fileName));
+        sha = sha.replace('^', '');
+
+        return gitCommand(root, 'show', `${sha}:./${file}`);
+    }
+}