[Patch] "strace ./app.exe" probably runs application from /bin

[Christian Franke <Christian dot Franke at t-online dot de>]

Running an application with strace from current directory may not work 
as expected.
The "./" is not passed to CreateProcess() and the default app search 
rules apply
(1. strace.exe directory,  2. cwd, ..., 6. PATH)

Therefore, an old version of the same app already installed in /bin may 
be run instead.


Testcase:

$ cd /tmp

$ cp /bin/date.exe ./uname.exe

$ date
Sat Jun  2 16:34:23     2007

$ uname
CYGWIN_NT-5.1

$ ./uname
Sat Jun  2 16:34:24     2007

$ strace -o nul ./uname
CYGWIN_NT-5.1

Workaround:

$ strace -o nul ././uname
Sat Jun  2 16:34:25     2007


The attached patch should fix this.

2007-06-02  Christian Franke <franke@computer.org>

	* strace.cc (create_child): Don't remove current directory
	from application path.


Christian

--- cygwin-1.5.24-2.orig/winsup/utils/strace.cc	2006-05-24 18:50:50.001000000 +0200
+++ cygwin-1.5.24-2/winsup/utils/strace.cc	2007-06-02 16:04:39.281250000 +0200
@@ -313,7 +313,19 @@ create_child (char **argv)
   BOOL ret;
   DWORD flags;
 
-  *argv = cygpath (*argv, NULL);
+  if (strncmp(*argv, "./", 2) == 0)
+    {
+      // cygpath() removes "./". Add another to avoid that
+      // CreateProcess() uses its application search rules
+      // (1. app dir, 2. cwd, ..., 6. PATH).
+      char arg0[2 + strlen(*argv) + 1];
+      strcpy (arg0, "./");
+      strcpy (arg0+2, *argv);
+      *argv = cygpath (arg0, NULL);
+    }
+  else
+    *argv = cygpath (*argv, NULL);
+
   memset (&si, 0, sizeof (si));
   si.cb = sizeof (si);