--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/extract/src/astring.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,208 @@
+#include "astring.h"
+#include "mem.h"
+#include "memento.h"
+
+#include <assert.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+void extract_astring_init(extract_astring_t *string)
+{
+	string->chars = NULL;
+	string->chars_num = 0;
+}
+
+void extract_astring_free(extract_alloc_t *alloc, extract_astring_t *string)
+{
+	extract_free(alloc, &string->chars);
+	extract_astring_init(string);
+}
+
+
+int extract_astring_catl(extract_alloc_t *alloc, extract_astring_t *string, const char *s, size_t s_len)
+{
+	if (extract_realloc2(alloc, &string->chars, string->chars_num+1, string->chars_num + s_len + 1))
+		return -1;
+	/* Coverity doesn't seem to realise that extract_realloc2() modifies
+	string->chars. */
+	/* coverity[deref_parm_field_in_call] */
+	memcpy(string->chars + string->chars_num, s, s_len);
+	string->chars[string->chars_num + s_len] = 0;
+	string->chars_num += s_len;
+	return 0;
+}
+
+int extract_astring_catc(extract_alloc_t *alloc, extract_astring_t *string, char c)
+{
+	return extract_astring_catl(alloc, string, &c, 1);
+}
+
+int extract_astring_cat(extract_alloc_t *alloc, extract_astring_t *string, const char *s)
+{
+	return extract_astring_catl(alloc, string, s, strlen(s));
+}
+
+int extract_astring_catf(extract_alloc_t *alloc, extract_astring_t *string, const char *format, ...)
+{
+	char    *buffer = NULL;
+	int      e;
+	va_list  va;
+
+	va_start(va, format);
+	e = extract_vasprintf(alloc, &buffer, format, va);
+	va_end(va);
+	if (e < 0) return e;
+	e = extract_astring_cat(alloc, string, buffer);
+	extract_free(alloc, &buffer);
+
+	return e;
+}
+
+int extract_astring_truncate(extract_astring_t *content, int len)
+{
+	assert((size_t) len <= content->chars_num);
+
+	content->chars_num -= len;
+	content->chars[content->chars_num] = 0;
+
+	return 0;
+}
+
+int extract_astring_char_truncate_if(extract_astring_t *content, char c)
+{
+	if (content->chars_num && content->chars[content->chars_num-1] == c)
+		extract_astring_truncate(content, 1);
+
+	return 0;
+}
+
+int extract_astring_catc_unicode(extract_alloc_t  *alloc,
+				extract_astring_t *string,
+				int                c,
+				int                xml,
+				int                ascii_ligatures,
+				int                ascii_dash,
+				int                ascii_apostrophe)
+{
+	int ret = -1;
+
+	if (0) {}
+
+	/* Escape XML special characters. */
+	else if (xml && c == '<')  extract_astring_cat(alloc, string, "&lt;");
+	else if (xml && c == '>')  extract_astring_cat(alloc, string, "&gt;");
+	else if (xml && c == '&')  extract_astring_cat(alloc, string, "&amp;");
+	else if (xml && c == '"')  extract_astring_cat(alloc, string, "&quot;");
+	else if (xml && c == '\'') extract_astring_cat(alloc, string, "&apos;");
+
+	/* Expand ligatures. */
+	else if (ascii_ligatures && c == 0xFB00)
+	{
+		if (extract_astring_cat(alloc, string, "ff")) goto end;
+	}
+	else if (ascii_ligatures && c == 0xFB01)
+	{
+		if (extract_astring_cat(alloc, string, "fi")) goto end;
+	}
+	else if (ascii_ligatures && c == 0xFB02)
+	{
+		if (extract_astring_cat(alloc, string, "fl")) goto end;
+	}
+	else if (ascii_ligatures && c == 0xFB03)
+	{
+		if (extract_astring_cat(alloc, string, "ffi")) goto end;
+	}
+	else if (ascii_ligatures && c == 0xFB04)
+	{
+		if (extract_astring_cat(alloc, string, "ffl")) goto end;
+	}
+
+	/* Convert some special characters to ascii. */
+	else if (ascii_dash && c == 0x2212)
+	{
+		if (extract_astring_catc(alloc, string, '-')) goto end;
+	}
+	else if (ascii_apostrophe && c == 0x2019)
+	{
+		if (extract_astring_catc(alloc, string, '\'')) goto end;
+	}
+
+	/* Output ASCII verbatim. */
+	else if (c >= 32 && c <= 127)
+	{
+		if (extract_astring_catc(alloc, string, (char) c)) goto end;
+	}
+
+	/* Escape all other characters. */
+	else if (xml)
+	{
+		char	buffer[32];
+		if (c < 32 && (c != 0x9 && c != 0xa && c != 0xd))
+		{
+			/* Illegal xml character; see
+			https://www.w3.org/TR/xml/#charsets. We replace with
+			0xfffd, the unicode replacement character. */
+			c = 0xfffd;
+		}
+		snprintf(buffer, sizeof(buffer), "&#x%x;", c);
+		if (extract_astring_cat(alloc, string, buffer)) goto end;
+	}
+	else
+	{
+		/* Use utf8. */
+		if (c < 0x80)
+		{
+			if (extract_astring_catc(alloc, string, (char) c)) return -1;
+		}
+		else if (c < 0x0800)
+		{
+			char cc[2] = {	(char) (((c >> 6) & 0x1f) | 0xc0),
+					(char) (((c >> 0) & 0x3f) | 0x80) };
+			if (extract_astring_catl(alloc, string, cc, sizeof(cc))) return -1;
+		}
+		else if (c < 0x10000)
+		{
+			char cc[3] = {	(char) (((c >> 12) & 0x0f) | 0xe0),
+					(char) (((c >>  6) & 0x3f) | 0x80),
+					(char) (((c >>  0) & 0x3f) | 0x80) };
+			if (extract_astring_catl(alloc, string, cc, sizeof(cc))) return -1;
+		}
+		else if (c < 0x110000)
+		{
+			char cc[4] = {	(char) (((c >> 18) & 0x07) | 0xf0),
+					(char) (((c >> 12) & 0x3f) | 0x80),
+					(char) (((c >>  6) & 0x3f) | 0x80),
+					(char) (((c >>  0) & 0x3f) | 0x80) };
+			if (extract_astring_catl(alloc, string, cc, sizeof(cc))) return -1;
+		}
+		else
+		{
+			/* Use replacement character. */
+			char cc[4] = { (char) 0xef, (char) 0xbf, (char) 0xbd, 0};
+			if (extract_astring_catl(alloc, string, cc, sizeof(cc))) return -1;
+		}
+	}
+
+	ret = 0;
+
+end:
+	return ret;
+}
+
+int extract_astring_catc_unicode_xml(extract_alloc_t *alloc, extract_astring_t *string, int c)
+{
+	/* FIXME: better to use ascii_ligatures=0, but that requires updates to
+	expected output files. */
+	return extract_astring_catc_unicode(
+					alloc,
+					string,
+					c,
+					1 /*xml*/,
+					1 /*ascii_ligatures*/,
+					0 /*ascii_dash*/,
+					0 /*ascii_apostrophe*/
+					);
+}