tweaks: use memory on the stack instead of calling malloc() and free()

src/files.c

@@ -2713,8 +2713,7 @@ char *input_tab(char *buf, bool allow_files, size_t *place,
 	char *mzero, *glued;
 	const char *lastslash = revstrstr(buf, "/", buf + *place);
 	size_t lastslash_len = (lastslash == NULL) ? 0 : lastslash - buf + 1;
-	char *match1 = charalloc(mb_cur_max());
-	char *match2 = charalloc(mb_cur_max());
+	char match1[mb_cur_max()], match2[mb_cur_max()];
 	int match1_len, match2_len;
 
 	/* Get the number of characters that all matches have in common. */
@@ -2735,9 +2734,6 @@ char *input_tab(char *buf, bool allow_files, size_t *place,
 	    common_len += match1_len;
 	}
 
-	free(match1);
-	free(match2);
-
 	mzero = charalloc(lastslash_len + common_len + 1);
 
 	strncpy(mzero, buf, lastslash_len);

src/utils.c

@@ -303,9 +303,8 @@ const char *fixbounds(const char *r)
  * a separate word?  That is: is it not part of a longer word?*/
 bool is_separate_word(size_t position, size_t length, const char *buf)
 {
-    char *before = charalloc(mb_cur_max()), *after = charalloc(mb_cur_max());
+    char before[mb_cur_max()], after[mb_cur_max()];
     size_t word_end = position + length;
-    bool retval;
 
     /* Get the characters before and after the word, if any. */
     parse_mbchar(buf + move_mbleft(buf, position), before, NULL);
@@ -314,13 +313,8 @@ bool is_separate_word(size_t position, size_t length, const char *buf)
     /* If the word starts at the beginning of the line OR the character before
      * the word isn't a letter, and if the word ends at the end of the line OR
      * the character after the word isn't a letter, we have a whole word. */
-    retval = (position == 0 || !is_alpha_mbchar(before)) &&
-		(word_end == strlen(buf) || !is_alpha_mbchar(after));
-
-    free(before);
-    free(after);
-
-    return retval;
+    return ((position == 0 || !is_alpha_mbchar(before)) &&
+		(buf[word_end] == '\0' || !is_alpha_mbchar(after)));
 }
 #endif /* !DISABLE_SPELLER */