+/* If character code C has modifier masks, reflect them to the
+ character code if possible. Return the resulting code. */
+
+int
+char_resolve_modifier_mask (c)
+ int c;
+{
+ /* A non-ASCII character can't reflect modifier bits to the code. */
+ if (! ASCII_CHAR_P ((c & ~CHAR_MODIFIER_MASK)))
+ return c;
+
+ /* For Meta, Shift, and Control modifiers, we need special care. */
+ if (c & CHAR_SHIFT)
+ {
+ /* Shift modifier is valid only with [A-Za-z]. */
+ if ((c & 0377) >= 'A' && (c & 0377) <= 'Z')
+ c &= ~CHAR_SHIFT;
+ else if ((c & 0377) >= 'a' && (c & 0377) <= 'z')
+ c = (c & ~CHAR_SHIFT) - ('a' - 'A');
+ /* Shift modifier for control characters and SPC is ignored. */
+ else if ((c & ~CHAR_MODIFIER_MASK) <= 0x20)
+ c &= ~CHAR_SHIFT;
+ }
+ if (c & CHAR_CTL)
+ {
+ /* Simulate the code in lread.c. */
+ /* Allow `\C- ' and `\C-?'. */
+ if ((c & 0377) == ' ')
+ c &= ~0177 & ~ CHAR_CTL;
+ else if ((c & 0377) == '?')
+ c = 0177 | (c & ~0177 & ~CHAR_CTL);
+ /* ASCII control chars are made from letters (both cases),
+ as well as the non-letters within 0100...0137. */
+ else if ((c & 0137) >= 0101 && (c & 0137) <= 0132)
+ c &= (037 | (~0177 & ~CHAR_CTL));
+ else if ((c & 0177) >= 0100 && (c & 0177) <= 0137)
+ c &= (037 | (~0177 & ~CHAR_CTL));
+ }
+ if (c & CHAR_META)
+ {
+ /* Move the meta bit to the right place for a string. */
+ c = (c & ~CHAR_META) | 0x80;
+ }
+
+ return c;
+}
+
+