Windows: accept backslashes in file names

Without this patch, a warning gets printed for any .yang files that are
read using native path names:

 libyang[1]: File name "D:\a\oopt-gnpy-libyang\oopt-gnpy-libyang\tests\yang\ietf-network@2018-02-26.yang" does not match module name "ietf-network".

compat/compat.c

@@ -347,3 +347,23 @@ setenv(const char *name, const char *value, int overwrite)
 #error No setenv() implementation for this platform is available.
 #endif
 #endif
+
+/**
+ * @brief Equivalent of strrchr(s, '/') which also supports Windows path on Windows
+ */
+char *strrchr_fname_slash(const char *s)
+{
+#ifndef _WIN32
+    return strrchr(s, '/');
+#else
+    char *slash = strrchr(s, '/');
+    char *backslash = strrchr(s, '\\');
+    if (slash && backslash) {
+        retturn slash > backslash ? slash : backslash;
+    } else if (slash) {
+        return slash;
+    } else {
+        return backslash;
+    }
+#endif
+}

compat/compat.h.in

@@ -210,4 +210,6 @@ char *strptime(const char *s, const char *format, struct tm *tm);
 int setenv(const char *name, const char *value, int overwrite);
 #endif
 
+char *strrchr_fname_slash(const char *s);
+
 #endif /* _COMPAT_H_ */

src/tree_schema.c

@@ -1832,7 +1832,7 @@ lys_parse_in(struct ly_ctx *ctx, struct ly_in *in, LYS_INFORMAT format,
     switch (in->type) {
     case LY_IN_FILEPATH:
         /* check that name and revision match filename */
-        filename = strrchr(in->method.fpath.filepath, '/');
+        filename = strrchr_fname_slash(in->method.fpath.filepath);
         if (!filename) {
             filename = in->method.fpath.filepath;
         } else {

src/tree_schema_common.c

@@ -740,7 +740,7 @@ lysp_load_module_check(const struct ly_ctx *ctx, struct lysp_module *mod, struct
     }
     if (info->path) {
         /* check that name and revision match filename */
-        filename = strrchr(info->path, '/');
+        filename = strrchr_fname_slash(info->path);
         if (!filename) {
             filename = info->path;
         } else {

tools/lint/common.c

@@ -54,7 +54,7 @@ parse_schema_path(const char *path, char **dir, char **module)
 
     /* split the path to dirname and basename for further work */
     *dir = strdup(path);
-    *module = strrchr(*dir, '/');
+    *module = strrchr_fname_slash(*dir);
     if (!(*module)) {
         *module = *dir;
         *dir = strdup("./");