Merge pull request #4421 from krader1961/consistent-unicode

Use \uXXXX consistently for unicode code points
(cherry picked from commit 6b2e84be0e)

Backporting to 2.7.0 branch just to try and keep changes between master
and this branch as minimal as possible.

src/common.cpp

@@ -7,6 +7,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <limits.h>
+#include <pthread.h>
 #include <stdarg.h>
 #include <stddef.h>
 #include <stdint.h>
@@ -486,14 +487,14 @@ wchar_t *quote_end(const wchar_t *pos) {
 }
 
 void fish_setlocale() {
-    // Use the Unicode "ellipsis" symbol if it can be encoded using the current locale.
-    ellipsis_char = can_be_encoded(L'\x2026') ? L'\x2026' : L'$';
-
-    // Use the Unicode "return" symbol if it can be encoded using the current locale.
-    omitted_newline_char = can_be_encoded(L'\x23CE') ? L'\x23CE' : L'~';
-
-    // solid circle unicode character if it is able, fallback to the hash character
-    obfuscation_read_char = can_be_encoded(L'\u25cf') ? L'\u25cf' : L'#';
+    // Use various Unicode symbols if they can be encoded using the current locale, else a simple
+    // ASCII char alternative. All of the can_be_encoded() invocations should return the same
+    // true/false value since the code points are in the BMP but we're going to be paranoid. This
+    // is also technically wrong if we're not in a Unicode locale but we expect (or hope)
+    // can_be_encoded() will return false in that case.
+    ellipsis_char = can_be_encoded(L'\u2026') ? L'\u2026' : L'$';          // "horizontal ellipsis"
+    omitted_newline_char = can_be_encoded(L'\u23CE') ? L'\u23CE' : L'~';   // "return"
+    obfuscation_read_char = can_be_encoded(L'\u25CF') ? L'\u25CF' : L'#';  // "black circle"
 }
 
 long read_blocked(int fd, void *buf, size_t count) {