Merge branch 'js/var-git-shell-path'

"git var GIT_SHELL_PATH" should report the path to the shell used
to spawn external commands, but it didn't do so on Windows, which
has been corrected.

* js/var-git-shell-path:
  var(win32): do report the GIT_SHELL_PATH that is actually used
  run-command: declare the `git_shell_path()` function globally
  run-command(win32): resolve the path to the Unix shell early
  mingw(is_msys2_sh): handle forward slashes in the `sh.exe` path, too
  win32: override `fspathcmp()` with a directory separator-aware version
  strvec: declare the `strvec_push_nodup()` function globally
  run-command: refactor getting the Unix shell path into its own function

builtin/var.c

@@ -12,6 +12,7 @@
 #include "refs.h"
 #include "path.h"
 #include "strbuf.h"
+#include "run-command.h"
 
 static const char var_usage[] = "git var (-l | <variable>)";
 
@@ -51,7 +52,7 @@ static char *default_branch(int ident_flag UNUSED)
 
 static char *shell_path(int ident_flag UNUSED)
 {
-	return xstrdup(SHELL_PATH);
+	return git_shell_path();
 }
 
 static char *git_attr_val_system(int ident_flag UNUSED)

compat/mingw.c

@@ -1546,7 +1546,7 @@ static int is_msys2_sh(const char *cmd)
 		return ret;
 	}
 
-	if (ends_with(cmd, "\\sh.exe")) {
+	if (ends_with(cmd, "\\sh.exe") || ends_with(cmd, "/sh.exe")) {
 		static char *sh;
 
 		if (!sh)

compat/win32/path-utils.c

@@ -1,4 +1,5 @@
 #include "../../git-compat-util.h"
+#include "../../environment.h"
 
 int win32_has_dos_drive_prefix(const char *path)
 {
@@ -50,3 +51,39 @@ int win32_offset_1st_component(const char *path)
 
 	return pos + is_dir_sep(*pos) - path;
 }
+
+int win32_fspathncmp(const char *a, const char *b, size_t count)
+{
+	int diff;
+
+	for (;;) {
+		if (!count--)
+			return 0;
+		if (!*a)
+			return *b ? -1 : 0;
+		if (!*b)
+			return +1;
+
+		if (is_dir_sep(*a)) {
+			if (!is_dir_sep(*b))
+				return -1;
+			a++;
+			b++;
+			continue;
+		} else if (is_dir_sep(*b))
+			return +1;
+
+		diff = ignore_case ?
+			(unsigned char)tolower(*a) - (int)(unsigned char)tolower(*b) :
+			(unsigned char)*a - (int)(unsigned char)*b;
+		if (diff)
+			return diff;
+		a++;
+		b++;
+	}
+}
+
+int win32_fspathcmp(const char *a, const char *b)
+{
+	return win32_fspathncmp(a, b, (size_t)-1);
+}

compat/win32/path-utils.h

@@ -29,5 +29,9 @@ static inline int win32_has_dir_sep(const char *path)
 #define has_dir_sep(path) win32_has_dir_sep(path)
 int win32_offset_1st_component(const char *path);
 #define offset_1st_component win32_offset_1st_component
+int win32_fspathcmp(const char *a, const char *b);
+#define fspathcmp win32_fspathcmp
+int win32_fspathncmp(const char *a, const char *b, size_t count);
+#define fspathncmp win32_fspathncmp
 
 #endif

dir.c

@@ -95,7 +95,7 @@ int count_slashes(const char *s)
 	return cnt;
 }
 
-int fspathcmp(const char *a, const char *b)
+int git_fspathcmp(const char *a, const char *b)
 {
 	return ignore_case ? strcasecmp(a, b) : strcmp(a, b);
 }
@@ -105,7 +105,7 @@ int fspatheq(const char *a, const char *b)
 	return !fspathcmp(a, b);
 }
 
-int fspathncmp(const char *a, const char *b, size_t count)
+int git_fspathncmp(const char *a, const char *b, size_t count)
 {
 	return ignore_case ? strncasecmp(a, b, count) : strncmp(a, b, count);
 }

dir.h

@@ -541,9 +541,9 @@ int remove_dir_recursively(struct strbuf *path, int flag);
  */
 int remove_path(const char *path);
 
-int fspathcmp(const char *a, const char *b);
+int git_fspathcmp(const char *a, const char *b);
 int fspatheq(const char *a, const char *b);
-int fspathncmp(const char *a, const char *b, size_t count);
+int git_fspathncmp(const char *a, const char *b, size_t count);
 unsigned int fspathhash(const char *str);
 
 /*

git-compat-util.h

@@ -506,6 +506,14 @@ static inline int git_offset_1st_component(const char *path)
 #define offset_1st_component git_offset_1st_component
 #endif
 
+#ifndef fspathcmp
+#define fspathcmp git_fspathcmp
+#endif
+
+#ifndef fspathncmp
+#define fspathncmp git_fspathncmp
+#endif
+
 #ifndef is_valid_path
 #define is_valid_path(path) 1
 #endif

run-command.c

@@ -274,17 +274,24 @@ int sane_execvp(const char *file, char * const argv[])
 	return -1;
 }
 
+char *git_shell_path(void)
+{
+#ifndef GIT_WINDOWS_NATIVE
+	return xstrdup(SHELL_PATH);
+#else
+	char *p = locate_in_PATH("sh");
+	convert_slashes(p);
+	return p;
+#endif
+}
+
 static const char **prepare_shell_cmd(struct strvec *out, const char **argv)
 {
 	if (!argv[0])
 		BUG("shell command is empty");
 
 	if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
-#ifndef GIT_WINDOWS_NATIVE
+		strvec_push_nodup(out, git_shell_path());
-		strvec_push(out, SHELL_PATH);
-#else
-		strvec_push(out, "sh");
-#endif
 		strvec_push(out, "-c");
 
 		/*

run-command.h

@@ -195,6 +195,11 @@ int is_executable(const char *name);
  */
 int exists_in_PATH(const char *command);
 
+/**
+ * Return the path that is used to execute Unix shell command-lines.
+ */
+char *git_shell_path(void);
+
 /**
  * Start a sub-process. Takes a pointer to a `struct child_process`
  * that specifies the details and returns pipe FDs (if requested).

strvec.c

@@ -10,7 +10,7 @@ void strvec_init(struct strvec *array)
 	memcpy(array, &blank, sizeof(*array));
 }
 
-static void strvec_push_nodup(struct strvec *array, const char *value)
+void strvec_push_nodup(struct strvec *array, char *value)
 {
 	if (array->v == empty_strvec)
 		array->v = NULL;

strvec.h

@@ -46,6 +46,9 @@ void strvec_init(struct strvec *);
 /* Push a copy of a string onto the end of the array. */
 const char *strvec_push(struct strvec *, const char *);
 
+/* Push an allocated string onto the end of the array, taking ownership. */
+void strvec_push_nodup(struct strvec *array, char *value);
+
 /**
  * Format a string and push it onto the end of the array. This is a
  * convenience wrapper combining `strbuf_addf` and `strvec_push`.

t/t0007-git-var.sh

@@ -157,7 +157,7 @@ test_expect_success POSIXPERM 'GIT_SHELL_PATH points to a valid executable' '
 test_expect_success MINGW 'GIT_SHELL_PATH points to a suitable shell' '
 	shellpath=$(git var GIT_SHELL_PATH) &&
 	case "$shellpath" in
-	*sh) ;;
+	[A-Z]:/*/sh.exe) test -f "$shellpath";;
 	*) return 1;;
 	esac
 '