Merge branch 'ma/locate-in-path-for-windows'

"git bisect visualize" stopped running "gitk" on Git for Windows
when the command was reimplemented in C around Git 2.34 timeframe.
This has been corrected.

* ma/locate-in-path-for-windows:
  docs: update when `git bisect visualize` uses `gitk`
  compat/mingw: implement a native locate_in_PATH()
  run-command: conditionally define locate_in_PATH()

Author: gitster

Documentation/git-bisect.txt

@@ -204,9 +204,14 @@ as an alternative to `visualize`):
 $ git bisect visualize
 ------------
 
-If the `DISPLAY` environment variable is not set, 'git log' is used
-instead.  You can also give command-line options such as `-p` and
-`--stat`.
+Git detects a graphical environment through various environment variables:
+`DISPLAY`, which is set in X Window System environments on Unix systems.
+`SESSIONNAME`, which is set under Cygwin in interactive desktop sessions.
+`MSYSTEM`, which is set under Msys2 and Git for Windows.
+`SECURITYSESSIONID`, which may be set on macOS in interactive desktop sessions.
+
+If none of these environment variables is set, 'git log' is used instead.
+You can also give command-line options such as `-p` and `--stat`.
 
 ------------
 $ git bisect visualize --stat

compat/mingw.c

@@ -1347,6 +1347,11 @@ static char *path_lookup(const char *cmd, int exe_only)
 	return prog;
 }
 
+char *mingw_locate_in_PATH(const char *cmd)
+{
+	return path_lookup(cmd, 0);
+}
+
 static const wchar_t *wcschrnul(const wchar_t *s, wchar_t c)
 {
 	while (*s && *s != c)

compat/mingw.h

@@ -177,6 +177,9 @@ pid_t waitpid(pid_t pid, int *status, int options);
 #define kill mingw_kill
 int mingw_kill(pid_t pid, int sig);
 
+#define locate_in_PATH mingw_locate_in_PATH
+char *mingw_locate_in_PATH(const char *cmd);
+
 #ifndef NO_OPENSSL
 #include <openssl/ssl.h>
 static inline int mingw_SSL_set_fd(SSL *ssl, int fd)

run-command.c

@@ -170,6 +170,7 @@ int is_executable(const char *name)
 	return st.st_mode & S_IXUSR;
 }
 
+#ifndef locate_in_PATH
 /*
  * Search $PATH for a command.  This emulates the path search that
  * execvp would perform, without actually executing the command so it
@@ -218,6 +219,7 @@ static char *locate_in_PATH(const char *file)
 	strbuf_release(&buf);
 	return NULL;
 }
+#endif
 
 int exists_in_PATH(const char *command)
 {