VcsBase: Introduce vcsExecWithHandler()

Before, vcsExec() returned already started VcsCommand.
Later, callers of vcsExec() were establishing connections
to the retured VcsCommand::done() signal. However, when
process fails to start (e.g. because of non-existing
executable), the done() signal may be emitted synchonously
from inside VcsCommand::start(). In this scenario
callers of VcsCommand could miss the emission of done()
signal and connect to already finished command.

Instead, provide a vcsExecWithHandler() function which
takes a handler to be called when command finished.
In addition it takes the context object, too.
Don't return VcsCommand from vcsExec() anymore.

Change-Id: I2fb5fbe5d27632ea039c650d37e5d7d1b60cebc0
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

1 files changed, 8 insertions, 8 deletions

diff --git a/src/plugins/git/gitplugin.cpp b/src/plugins/git/gitplugin.cpp
index ae3c98b42b..974dde851f 100644
--- a/src/plugins/git/gitplugin.cpp
+++ b/src/plugins/git/gitplugin.cpp
@@ -1572,19 +1572,19 @@ void GitPluginPrivate::instantBlame()
     const QFileInfo fi(filePath.toString());
     const Utils::FilePath workingDirectory = Utils::FilePath::fromString(fi.path());
     const QString lineString = QString("%1,%1").arg(line);
-    const VcsCommand *command = GitClient::instance()->vcsExec(
-                workingDirectory, {"blame", "-p", "-L", lineString, "--", filePath.toString()},
-                nullptr, false, RunFlags::NoOutput);
-    connect(command, &VcsCommand::done, this, [command, filePath, line, this] {
-        if (command->result() == ProcessResult::FinishedWithError &&
-                command->cleanedStdErr().contains("no such path")) {
+    const auto commandHandler = [this, filePath, line](const CommandResult &result) {
+        if (result.result() == ProcessResult::FinishedWithError &&
+                result.cleanedStdErr().contains("no such path")) {
             disconnect(m_blameCursorPosConn);
             return;
         }
-        const QString output = command->cleanedStdOut();
+        const QString output = result.cleanedStdOut();
         const CommitInfo info = parseBlameOutput(output.split('\n'), filePath, m_author);
         m_blameMark.reset(new BlameMark(filePath, line, info));
-    });
+    };
+    GitClient::instance()->vcsExecWithHandler(workingDirectory,
+                           {"blame", "-p", "-L", lineString, "--", filePath.toString()},
+                           this, commandHandler, RunFlags::NoOutput, false);
 }
 
 void GitPluginPrivate::stopInstantBlame()