feature/android 55634b5f79f 4/5: Update Android port

[Po Lu]

branch: feature/android
commit 55634b5f79ffb723eebe4a2f6c773213011e6a61
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Update Android port
    
    * src/android.c (android_build_string): Convert the text to
    UTF-16, and create the Java string using that.
    (android_build_jstring): Update comment.
    * src/androidmenu.c (android_init_emacs_context_menu): Add
    String argument to `addItem'.
    (android_menu_show): Correctly pass help strings in regular menu
    items.
    * src/sfnt.c (_sfnt_swap16, _sfnt_swap32): Avoid reserved names.
---
 src/android.c     | 38 +++++++++++++++++++++++++++++---------
 src/androidmenu.c | 17 +++++++++++++++--
 src/sfnt.c        |  8 ++++----
 3 files changed, 48 insertions(+), 15 deletions(-)

diff --git a/src/android.c b/src/android.c
index e8f076771b9..5420fbde9b9 100644
--- a/src/android.c
+++ b/src/android.c
@@ -5244,28 +5244,48 @@ android_build_string (Lisp_Object text)
 {
   Lisp_Object encoded;
   jstring string;
+  size_t nchars;
+  jchar *characters;
+  USE_SAFE_ALLOCA;
 
-  encoded = ENCODE_UTF_8 (text);
+  encoded = code_convert_string_norecord (text, Qutf_16le,
+                                         true);
+  nchars = (SBYTES (encoded) / sizeof (jchar));
 
-  /* Note that Java expects this string to be in ``modified UTF
-     encoding'', which is actually UTF-8, except with NUL encoded as a
-     two-byte sequence.  The only consequence of passing an actual
-     UTF-8 string is that NUL bytes cannot be represented, which is
-     not really of consequence.  */
-  string = (*android_java_env)->NewStringUTF (android_java_env,
-                                             SSDATA (encoded));
+  /* Encode the string as UTF-16 prior to creating the string.
+     Copy the string to a separate buffer in order to preserve
+     alignment.  */
+
+  characters = SAFE_ALLOCA (SBYTES (encoded));
+  memcpy (characters, SDATA (encoded), SBYTES (encoded));
+
+  /* Create the string.  */
+  string
+    = (*android_java_env)->NewString (android_java_env,
+                                     characters, nchars);
   android_exception_check ();
 
+  SAFE_FREE ();
   return string;
 }
 
-/* Do the same, except TEXT is constant string data.  */
+/* Do the same, except TEXT is constant string data in ASCII or
+   UTF-8 containing no characters outside the Basic Multilingual
+   Plane.  */
 
 jstring
 android_build_jstring (const char *text)
 {
   jstring string;
 
+  /* Note that Java expects this string to be in ``modified UTF
+     encoding'', which is actually UTF-8, except with NUL
+     encoded as a two-byte sequence, and surrogate pairs encoded
+     in the three-byte extended encoding.  The only consequence
+     of passing an actual UTF-8 string is that NUL bytes and
+     characters requiring surrogate pairs cannot be represented,
+     which is not really of consequence.  */
+
   string = (*android_java_env)->NewStringUTF (android_java_env,
                                              text);
   android_exception_check ();
diff --git a/src/androidmenu.c b/src/androidmenu.c
index 2ba11aa1663..540b25cf602 100644
--- a/src/androidmenu.c
+++ b/src/androidmenu.c
@@ -98,7 +98,8 @@ android_init_emacs_context_menu (void)
   FIND_METHOD_STATIC (create_context_menu, "createContextMenu",
                      "(Ljava/lang/String;)Lorg/gnu/emacs/EmacsContextMenu;");
 
-  FIND_METHOD (add_item, "addItem", "(ILjava/lang/String;ZZZ)V");
+  FIND_METHOD (add_item, "addItem", "(ILjava/lang/String;ZZZ"
+              "Ljava/lang/String;)V");
   FIND_METHOD (add_submenu, "addSubmenu", "(Ljava/lang/String;"
               "Ljava/lang/String;Ljava/lang/String;)"
               "Lorg/gnu/emacs/EmacsContextMenu;");
@@ -411,6 +412,14 @@ android_menu_show (struct frame *f, int x, int y, int 
menuflags,
              title_string = (!NILP (item_name)
                              ? android_build_string (item_name)
                              : NULL);
+             help_string = NULL;
+
+             /* Menu items can have tool tips on Android 26 and
+                later.  In this case, set it to the help string.  */
+
+             if (android_get_current_api_level () >= 26
+                 && STRINGP (help))
+               help_string = android_build_string (help);
 
              /* Determine whether or not to display a check box.  */
 
@@ -424,11 +433,15 @@ android_menu_show (struct frame *f, int x, int y, int 
menuflags,
                                                   title_string,
                                                   (jboolean) !NILP (enable),
                                                   (jboolean) checkmark,
-                                                  (jboolean) !NILP (selected));
+                                                  (jboolean) !NILP (selected),
+                                                  help_string);
              android_exception_check ();
 
              if (title_string)
                ANDROID_DELETE_LOCAL_REF (title_string);
+
+             if (help_string)
+               ANDROID_DELETE_LOCAL_REF (help_string);
            }
 
          i += MENU_ITEMS_ITEM_LENGTH;
diff --git a/src/sfnt.c b/src/sfnt.c
index b4f587a4690..5b219bf6369 100644
--- a/src/sfnt.c
+++ b/src/sfnt.c
@@ -155,7 +155,7 @@ static uint32_t sfnt_table_names[] =
 /* Swap values from TrueType to system byte order.  */
 
 static void
-_sfnt_swap16 (uint16_t *value)
+sfnt_swap16_1 (uint16_t *value)
 {
 #ifndef WORDS_BIGENDIAN
   *value = bswap_16 (*value);
@@ -163,15 +163,15 @@ _sfnt_swap16 (uint16_t *value)
 }
 
 static void
-_sfnt_swap32 (uint32_t *value)
+sfnt_swap32_1 (uint32_t *value)
 {
 #ifndef WORDS_BIGENDIAN
   *value = bswap_32 (*value);
 #endif
 }
 
-#define sfnt_swap16(what) (_sfnt_swap16 ((uint16_t *) (what)))
-#define sfnt_swap32(what) (_sfnt_swap32 ((uint32_t *) (what)))
+#define sfnt_swap16(what) (sfnt_swap16_1 ((uint16_t *) (what)))
+#define sfnt_swap32(what) (sfnt_swap32_1 ((uint32_t *) (what)))
 
 /* Read the table directory from the file FD.  FD must currently be at
    the start of the file (or an offset defined in the TTC header, if