Merge branch 'bc/connect-plink' into maint

The connection initiation code for "ssh" transport tried to absorb
differences between the stock "ssh" and Putty-supplied "plink" and
its derivatives, but the logic to tell that we are using "plink"
variants were too loose and falsely triggered when "plink" appeared
anywhere in the path (e.g. "/home/me/bin/uplink/ssh").

* bc/connect-plink:
  connect: improve check for plink to reduce false positives
  t5601: fix quotation error leading to skipped tests
  connect: simplify SSH connection code path

diff --cc connect.c
index 391d211,1f7b769..c0144d8
--- 1/connect.c
--- 2/connect.c
+++ b/connect.c
@@@ -741,30 -739,41 +741,42 @@@ struct child_process *git_connect(int f
  
                                free(hostandport);
                                free(path);
 +                              free(conn);
                                return NULL;
+                       }
+ 
+                       ssh = getenv("GIT_SSH_COMMAND");
+                       if (ssh) {
+                               conn->use_shell = 1;
+                               putty = 0;
                        } else {
-                               ssh = getenv("GIT_SSH_COMMAND");
-                               if (ssh) {
-                                       conn->use_shell = 1;
-                                       putty = 0;
-                               } else {
-                                       ssh = getenv("GIT_SSH");
-                                       if (!ssh)
-                                               ssh = "ssh";
-                                       putty = !!strcasestr(ssh, "plink");
-                               }
- 
-                               argv_array_push(&conn->args, ssh);
-                               if (putty && !strcasestr(ssh, "tortoiseplink"))
-                                       argv_array_push(&conn->args, "-batch");
-                               if (port) {
-                                       /* P is for PuTTY, p is for OpenSSH */
-                                       argv_array_push(&conn->args, putty ? "-P" : "-p");
-                                       argv_array_push(&conn->args, port);
-                               }
-                               argv_array_push(&conn->args, ssh_host);
+                               const char *base;
+                               char *ssh_dup;
+ 
+                               ssh = getenv("GIT_SSH");
+                               if (!ssh)
+                                       ssh = "ssh";
+ 
+                               ssh_dup = xstrdup(ssh);
+                               base = basename(ssh_dup);
+ 
+                               tortoiseplink = !strcasecmp(base, "tortoiseplink") ||
+                                       !strcasecmp(base, "tortoiseplink.exe");
+                               putty = !strcasecmp(base, "plink") ||
+                                       !strcasecmp(base, "plink.exe") || tortoiseplink;
+ 
+                               free(ssh_dup);
+                       }
+ 
+                       argv_array_push(&conn->args, ssh);
+                       if (tortoiseplink)
+                               argv_array_push(&conn->args, "-batch");
+                       if (port) {
+                               /* P is for PuTTY, p is for OpenSSH */
+                               argv_array_push(&conn->args, putty ? "-P" : "-p");
+                               argv_array_push(&conn->args, port);
                        }
+                       argv_array_push(&conn->args, ssh_host);
                } else {
                        /* remove repo-local variables from the environment */
                        conn->env = local_repo_env;

diff --cc t/t5601-clone.sh
Simple merge