fix(ocr_bitmap): out of buffer memory copying the "last font tag" & use memmove (#1586)

* ASAN: process_spu copies overlapping buffers

* ocr_bitmap: Make sure there is enough room for the last_font_tag

* Update CHANGES.TXT

* Baseline formatting fixes

* fixup! Baseline formatting fixes

* fixup! fixup! Baseline formatting fixes

* Fix rust comment formatting

* cxx_options.copy_from_rust: Avoid "mutable reference to mutable static" warning

Author: jstrot

docs/CHANGES.TXT

@@ -37,6 +37,7 @@
 - Improvement: Ignore MXF Caption Essence Container version byte to enhance SRT subtitle extraction compatibility
 - New: Add tesseract page segmentation modes control with `--psm` flag
 - Fix: Resolve compile-time error about implicit declarations (#1646)
+- Fix: fatal out of memory error extracting from a VOB PS
 
 0.94 (2021-12-14)
 -----------------

src/lib_ccx/dvd_subtitle_decoder.c

@@ -384,7 +384,7 @@ int process_spu(struct lib_cc_decode *dec_ctx, unsigned char *buff, int length,
 
 	if (ctx->append == 1)
 	{
-		memcpy(ctx->buffer + ctx->len, buff, length);
+		memmove(ctx->buffer + ctx->len, buff, length);
 		ctx->len += length;
 		ctx->append = 0;
 	}

src/lib_ccx/ocr.c

@@ -620,6 +620,7 @@ char *ocr_bitmap(void *arg, png_color *palette, png_byte *alpha, unsigned char *
 					// realloc if memory allocated may be not enough
 					int length_needed = (new_text_out_iter - new_text_out) +
 							    (line_end - line_start) +
+							    (last_font_tag_end ? (last_font_tag_end - last_font_tag) : 0) +
 							    length_closing_font + 32;
 
 					if (length_needed > length)