Fix the getting of the Git author name when user.name isn't set

The config variable is not required, as Git will get the user's name
from other system settings, like the gecos field in /etc/passwd. So
adapt Qt Creator to use the same mechanism that Git does.

Change-Id: I255870833a024a36adf6ffff13ecb43cc0c45bbf
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>

src/plugins/git/gitclient.cpp

@@ -2484,8 +2484,19 @@ bool GitClient::getCommitData(const QString &workingDirectory,
             commitData.amendSHA1.clear();
         }
         if (!authorFromCherryPick) {
-            commitData.panelData.author = readConfigValue(workingDirectory, QLatin1String("user.name"));
+            // the format is:
-            commitData.panelData.email = readConfigValue(workingDirectory, QLatin1String("user.email"));
+            // Joe Developer <joedev@example.com> unixtimestamp +HHMM
+            QString author_info = readGitVar(workingDirectory, QLatin1String("GIT_AUTHOR_IDENT"));
+            int lt = author_info.lastIndexOf(QLatin1Char('<'));
+            int gt = author_info.lastIndexOf(QLatin1Char('>'));
+            if (gt == -1 || uint(lt) > uint(gt)) {
+                // shouldn't happen!
+                commitData.panelData.author.clear();
+                commitData.panelData.email.clear();
+            } else {
+                commitData.panelData.author = author_info.left(lt - 1);
+                commitData.panelData.email = author_info.mid(lt + 1, gt - lt - 1);
+            }
         }
         // Commit: Get the commit template
         QString templateFilename = gitDirectory.absoluteFilePath(QLatin1String("MERGE_MSG"));
@@ -3083,14 +3094,26 @@ bool GitClient::synchronousStashList(const QString &workingDirectory,
 
 // Read a single-line config value, return trimmed
 QString GitClient::readConfigValue(const QString &workingDirectory, const QString &configVar) const
+{
+    QStringList arguments;
+    arguments << QLatin1String("config") << configVar;
+    return readOneLine(workingDirectory, arguments);
+}
+
+QString GitClient::readGitVar(const QString &workingDirectory, const QString &configVar) const
+{
+    QStringList arguments;
+    arguments << QLatin1String("var") << configVar;
+    return readOneLine(workingDirectory, arguments);
+}
+
+QString GitClient::readOneLine(const QString &workingDirectory, const QStringList &arguments) const
 {
     // msysGit always uses UTF-8 for configuration:
     // https://github.com/msysgit/msysgit/wiki/Git-for-Windows-Unicode-Support#convert-config-files
     static QTextCodec *codec = HostOsInfo::isWindowsHost()
             ? QTextCodec::codecForName("UTF-8")
             : QTextCodec::codecForLocale();
-    QStringList arguments;
-    arguments << QLatin1String("config") << configVar;
 
     QByteArray outputText;
     if (!vcsFullySynchronousExec(workingDirectory, arguments, &outputText, 0, silentFlags))

src/plugins/git/gitclient.h

@@ -293,6 +293,7 @@ public:
                               const QString &messge, QString *name,
                               QString *errorMessage = 0) const;
 
+    QString readGitVar(const QString &workingDirectory, const QString &configVar) const;
     QString readConfigValue(const QString &workingDirectory, const QString &configVar) const;
 
     QTextCodec *encoding(const QString &workingDirectory, const QByteArray &configVar) const;
@@ -370,6 +371,8 @@ private:
     // determine version as '(major << 16) + (minor << 8) + patch' or 0.
     unsigned synchronousGitVersion(QString *errorMessage = 0) const;
 
+    QString readOneLine(const QString &workingDirectory, const QStringList &arguments) const;
+
     enum RevertResult { RevertOk, RevertUnchanged, RevertCanceled, RevertFailed };
     RevertResult revertI(QStringList files,
                          bool *isDirectory,