[PATCH] MinGW: Quote arguments for subprocesses that contain a single-quote

Before a process can be spawned by mingw_spawnve, arguments must be
surrounded by double-quotes if special characters are present.  This is
necessary because the startup code of the spawned process will expand
arguments that look like glob patterns.  "Normal" Windows command line
utilities expand only * and ?, but MSYS programs, including bash, are
different: They also expand braces, and this has already been taken care
of by compat/mingw.c:quote_arg().

But MSYS programs also treat single-quotes in a special way: Arguments
between single-quotes are spliced together (with spaces) into a word.
With this patch this treatment is avoided by quoting arguments that contain
single-quotes.

This lets t4252 pass on Windows.

Signed-off-by: Johannes Sixt <redacted>
---
 t4252 passes a --directory argument with a single-quote to git-am. As a
 consequence, this argument was spliced into a single word with the
 remaining arguments, including the mbox file name. Following that,
 git-mailsplit was called without a mailbox, upon which it waited for input
 on stdin.

 -- Hannes

 compat/mingw.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/compat/mingw.c b/compat/mingw.c
index 171fa85..2839d9d 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c

@@ -457,7 +457,7 @@ static const char *quote_arg(const char *arg)
 	const char *p = arg;
 	if (!*p) force_quotes = 1;
 	while (*p) {
-		if (isspace(*p) || *p == '*' || *p == '?' || *p == '{')
+		if (isspace(*p) || *p == '*' || *p == '?' || *p == '{' || *p == '\'')
 			force_quotes = 1;
 		else if (*p == '"')
 			n++;

-- 
1.6.2.1.224.g2225f