[PATCH v2 3/7] win32: override `fspathcmp()` with a directory separator-aware version

["Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>]

From: Johannes Schindelin <johannes.schindelin@gmx.de>

On Windows, the backslash is the directory separator, even if the
forward slash can be used, too, at least since Windows NT.

This means that the paths `a/b` and `a\b` are equivalent, and
`fspathcmp()` needs to be made aware of that fact.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 compat/win32/path-utils.c | 25 +++++++++++++++++++++++++
 compat/win32/path-utils.h |  2 ++
 dir.c                     |  2 +-
 dir.h                     |  2 +-
 git-compat-util.h         |  5 +++++
 5 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/compat/win32/path-utils.c b/compat/win32/path-utils.c
index ebf2f12eb66..af7ef957bbf 100644
--- a/compat/win32/path-utils.c
+++ b/compat/win32/path-utils.c
@@ -50,3 +50,28 @@ int win32_offset_1st_component(const char *path)
 
 	return pos + is_dir_sep(*pos) - path;
 }
+
+int win32_fspathcmp(const char *a, const char *b)
+{
+	int diff;
+
+	for (;;) {
+		if (!*a)
+			return !*b ? 0 : -1;
+		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 = (unsigned char)tolower(*(a++)) - (unsigned char)tolower(*(b++));
+		if (diff)
+			return diff;
+	}
+}
diff --git a/compat/win32/path-utils.h b/compat/win32/path-utils.h
index 65fa3b9263a..e3c2a79df74 100644
--- a/compat/win32/path-utils.h
+++ b/compat/win32/path-utils.h
@@ -29,5 +29,7 @@ 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
 
 #endif
diff --git a/dir.c b/dir.c
index b7a6625ebda..37d8e266b2c 100644
--- a/dir.c
+++ b/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);
 }
diff --git a/dir.h b/dir.h
index 69a76d8bdd3..947e3d77442 100644
--- a/dir.h
+++ b/dir.h
@@ -541,7 +541,7 @@ 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);
 unsigned int fspathhash(const char *str);
diff --git a/git-compat-util.h b/git-compat-util.h
index ca7678a379d..ac564a68987 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -506,6 +506,11 @@ 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 is_valid_path
 #define is_valid_path(path) 1
 #endif
-- 
gitgitgadget