From 726102c90a1ac6ff67b041b8855fd74815dd9979 Mon Sep 17 00:00:00 2001
From: Pat Thoyts <patthoyts@users.sourceforge.net>
Date: Fri, 6 Jul 2012 19:56:19 +0100
Subject: [PATCH] git-wrapper: ensure the child process exit code is returned.

The new compiled git wrapper failed to propagate the error code from the
wrapped process which causes problems when scripting git commands.
Also print error messages if something fails when launching the target
process.

This resolves github issue #43.

Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net>
---
 src/git-wrapper/git-wrapper.c | 71 +++++++++++++++++++++++++++++++++----------
 1 file changed, 55 insertions(+), 16 deletions(-)

diff --git a/src/git-wrapper/git-wrapper.c b/src/git-wrapper/git-wrapper.c
index 06184420..e4ee5905 100644
--- a/src/git-wrapper/git-wrapper.c
+++ b/src/git-wrapper/git-wrapper.c
@@ -11,12 +11,33 @@
 #include <windows.h>
 #include <shlwapi.h>
 #include <shellapi.h>
+#include <stdio.h>
 
-#ifdef __MSC_VER__
-int __stdcall wmain(void)
-#else
-int main(void)
-#endif
+static void
+PrintError(LPCWSTR wszPrefix, DWORD dwError)
+{
+    LPWSTR lpsz = NULL;
+    DWORD cch = 0;
+
+    cch = FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER
+                         | FORMAT_MESSAGE_FROM_SYSTEM
+                         | FORMAT_MESSAGE_IGNORE_INSERTS,
+                         NULL, dwError, LANG_NEUTRAL,
+                         (LPTSTR)&lpsz, 0, NULL);
+    if (cch < 1) {
+        cch = FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER
+                             | FORMAT_MESSAGE_FROM_STRING
+                             | FORMAT_MESSAGE_ARGUMENT_ARRAY,
+                             L"Code 0x%1!08x!",
+                             0, LANG_NEUTRAL, (LPTSTR)&lpsz, 0,
+                             (va_list*)&dwError);
+    }
+    fwprintf(stderr, L"%s: %s", wszPrefix, lpsz);
+    LocalFree((HLOCAL)lpsz);
+}
+
+int
+main(void)
 {
     int r = 1, wait = 1;
     WCHAR exepath[MAX_PATH], exe[MAX_PATH];
@@ -136,20 +157,29 @@ int main(void)
     {
         STARTUPINFO si;
         PROCESS_INFORMATION pi;
+        BOOL br = FALSE;
         ZeroMemory(&pi, sizeof(PROCESS_INFORMATION));
         ZeroMemory(&si, sizeof(STARTUPINFO));
         si.cb = sizeof(STARTUPINFO);
-        CreateProcess(exep,/* module: null means use command line */
-                      cmd,  /* modified command line */
-                      NULL, /* process handle inheritance */
-                      NULL, /* thread handle inheritance */
-                      TRUE, /* handles inheritable? */
-                      CREATE_UNICODE_ENVIRONMENT,
-                      NULL, /* environment: use parent */
-                      NULL, /* starting directory: use parent */
-                      &si, &pi);
-        if (wait)
-            WaitForSingleObject(pi.hProcess, INFINITE);
+        br = CreateProcess(exep,/* module: null means use command line */
+                           cmd,  /* modified command line */
+                           NULL, /* process handle inheritance */
+                           NULL, /* thread handle inheritance */
+                           TRUE, /* handles inheritable? */
+                           CREATE_UNICODE_ENVIRONMENT,
+                           NULL, /* environment: use parent */
+                           NULL, /* starting directory: use parent */
+                           &si, &pi);
+        if (br) {
+            if (wait)
+                WaitForSingleObject(pi.hProcess, INFINITE);
+            if (!GetExitCodeProcess(pi.hProcess, (DWORD *)&r))
+                PrintError(L"error reading exit code", GetLastError());
+            CloseHandle(pi.hProcess);
+        } else {
+            PrintError(L"error launching git", GetLastError());
+            r = 1;
+        }
     }
 
     free(cmd);
@@ -158,3 +188,12 @@ int main(void)
     SetConsoleCP(codepage);
     ExitProcess(r);
 }
+
+/*
+ * Local variables:
+ * mode: c
+ * indent-tabs-mode: nil
+ * c-basic-offset: 4
+ * tab-width: 4
+ * End:
+ */
-- 
2.11.4.GIT