Backport Git for Windows' pathconv adjustments

newlib/libc/stdlib/mbtowc_r.c

@@ -36,7 +36,7 @@ __ascii_mbtowc (struct _reent *r,
   if (n == 0)
     return -2;
 
-#ifdef __CYGWIN__
+#ifdef STRICTLY_7BIT_ASCII
   if ((wchar_t)*t >= 0x80)
     {
       _REENT_ERRNO(r) = EILSEQ;

newlib/libc/stdlib/wctomb_r.c

@@ -29,7 +29,7 @@ __ascii_wctomb (struct _reent *r,
   if (s == NULL)
     return 0;
 
-#ifdef __CYGWIN__
+#ifdef STRICTLY_7BIT_ASCII
   if ((size_t)wchar >= 0x80)
 #else
   if ((size_t)wchar >= 0x100)

winsup/cygwin/msys2_path_conv.cc

@@ -349,6 +349,55 @@ path_type find_path_start_and_type(const char** src, int recurse, const char* en
     if (no_pathconv)
       return NONE;
 
+    /* Let's not convert ~/.file to ~C:\msys64\.file */
+    if (*it == '~') {
+skip_p2w:
+        *src = end;
+        return NONE;
+    }
+
+    /*
+     * Prevent Git's :file.txt and :/message syntax from beeing modified.
+     */
+    if (*it == ':')
+        goto skip_p2w;
+
+    while (it != end && *it) {
+        switch (*it) {
+        case '`':
+        case '\'':
+        case '"':
+        case '*':
+        case '?':
+        case '[':
+        case ']':
+            goto skip_p2w;
+        case '/':
+            if (it + 1 < end && it[1] == '~')
+                goto skip_p2w;
+            break;
+        case ':':
+            // Avoid mangling IPv6 addresses
+            if (it + 1 < end && it[1] == ':')
+                goto skip_p2w;
+
+            // Leave Git's <rev>:./name syntax alone
+            if (it + 1 < end && it[1] == '.') {
+                if (it + 2 < end && it[2] == '/')
+                    goto skip_p2w;
+                if (it + 3 < end && it[2] == '.' && it[3] == '/')
+                    goto skip_p2w;
+            }
+            break;
+        case '@':
+            // Paths do not contain '@@'
+            if (it + 1 < end && it[1] == '@')
+                goto skip_p2w;
+        }
+        ++it;
+    }
+    it = *src;
+
     while (!isalnum(*it) && *it != '/' && *it != '\\' && *it != ':' && *it != '-' && *it != '.') {
         recurse = true;
         it = ++*src;
@@ -421,6 +470,8 @@ path_type find_path_start_and_type(const char** src, int recurse, const char* en
 
     int starts_with_minus = 0;
     int starts_with_minus_alpha = 0;
+    int only_dots = *it == '.';
+    int has_slashes = 0;
     if (*it == '-') {
       starts_with_minus = 1;
       it += 1;
@@ -464,11 +515,17 @@ path_type find_path_start_and_type(const char** src, int recurse, const char* en
                 if (ch == '/' && *(it2 + 1) == '/') {
                     return URL;
                 } else {
+                    if (!only_dots && !has_slashes)
+                        goto skip_p2w;
                     return POSIX_PATH_LIST;
                 }
             } else if (memchr(it2, '=', end - it2) == NULL) {
                 return SIMPLE_WINDOWS_PATH;
             }
+        } else if (ch != '.') {
+            only_dots = 0;
+            if (ch == '/' || ch == '\\')
+                has_slashes = 1;
         }
     }
 

winsup/cygwin/strfuncs.cc

@@ -616,7 +616,11 @@ _sys_mbstowcs (mbtowc_p f_mbtowc, wchar_t *dst, size_t dlen, const char *src,
 	     to store them in a symmetric way. */
 	  bytes = 1;
 	  if (dst)
+#ifdef STRICTLY_7BIT_ASCII
 	    *ptr = L'\xf000' | *pmbs;
+#else
+	    *ptr = *pmbs;
+#endif
 	  memset (&ps, 0, sizeof ps);
 	}