help (Windows): Display HTML in default browser using Windows' shell API

The system's default browser for displaying HTML help pages is now used
directly on Windows, instead of launching git-web--browser, which
requires a Unix shell.  Avoiding MSYS' bash when possible is good
because it avoids potential path translation issues.  In this case it is
not too hard to avoid launching a shell, so let's avoid it.

The Windows-specific code is implemented in compat/mingw.c to avoid
platform-specific code in the main code base.  On Windows, open_html is
provided as a define.  If open_html is not defined, git-web--browse is
used.  This approach avoids platform-specific ifdefs by using
per-function ifdefs.  The "ifndef open_html" together with the
introductory comment should sufficiently warn developers, so that they
hopefully will not break this mechanism.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/compat/mingw.c b/compat/mingw.c
index 3a05fe7..c0bc849 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -1017,3 +1017,25 @@ sig_handler_t mingw_signal(int sig, sig_handler_t handler)
 	timer_fn = handler;
 	return old;
 }
+
+static const char *make_backslash_path(const char *path)
+{
+	static char buf[PATH_MAX + 1];
+	char *c;
+
+	if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
+		die("Too long path: %.*s", 60, path);
+
+	for (c = buf; *c; c++) {
+		if (*c == '/')
+			*c = '\\';
+	}
+	return buf;
+}
+
+void mingw_open_html(const char *unixpath)
+{
+	const char *htmlpath = make_backslash_path(unixpath);
+	printf("Launching default browser to display HTML ...\n");
+	ShellExecute(NULL, "open", htmlpath, NULL, "\\", 0);
+}