Add fz_terminate_buffer function.

Non-destructively zero terminate a fz_buffer for use as a C string.

7 files changed, 21 insertions, 31 deletions

diff --git a/source/fitz/buffer.c b/source/fitz/buffer.c
index 13aae983..a2880659 100644
--- a/source/fitz/buffer.c
+++ b/source/fitz/buffer.c
@@ -152,6 +152,15 @@ fz_trim_buffer(fz_context *ctx, fz_buffer *buf)
 		fz_resize_buffer(ctx, buf, buf->len);
 }
 
+void
+fz_terminate_buffer(fz_context *ctx, fz_buffer *buf)
+{
+	/* ensure that there is a zero-byte after the end of the data */
+	if (buf->len + 1 > buf->cap)
+		fz_grow_buffer(ctx, buf);
+	buf->data[buf->len] = 0;
+}
+
 size_t
 fz_buffer_storage(fz_context *ctx, fz_buffer *buf, unsigned char **datap)
 {
@@ -165,10 +174,7 @@ fz_string_from_buffer(fz_context *ctx, fz_buffer *buf)
 {
 	if (!buf)
 		return "";
-
-	if (buf->data[buf->len-1] != 0)
-		fz_write_buffer_byte(ctx, buf, 0);
-
+	fz_terminate_buffer(ctx, buf);
 	return (const char *)buf->data;
 }
 
diff --git a/source/fitz/stext-search.c b/source/fitz/stext-search.c
index 3904b01d..99584581 100644
--- a/source/fitz/stext-search.c
+++ b/source/fitz/stext-search.c
@@ -278,9 +278,8 @@ fz_copy_selection(fz_context *ctx, fz_stext_page *page, fz_rect rect)
 		}
 	}
 
-	fz_write_buffer_byte(ctx, buffer, 0);
-
-	fz_buffer_extract(ctx, buffer, &s);
+	fz_terminate_buffer(ctx, buffer);
+	fz_buffer_extract(ctx, buffer, &s); /* take over the data */
 	fz_drop_buffer(ctx, buffer);
 	return (char*)s;
 }
diff --git a/source/html/epub-doc.c b/source/html/epub-doc.c
index 590004f6..cf7f1ecf 100644
--- a/source/html/epub-doc.c
+++ b/source/html/epub-doc.c
@@ -256,7 +256,6 @@ epub_parse_chapter(fz_context *ctx, epub_document *doc, const char *path)
 	fz_dirname(base_uri, path, sizeof base_uri);
 
 	buf = fz_read_archive_entry(ctx, zip, path);
-	fz_write_buffer_byte(ctx, buf, 0);
 
 	ch = fz_malloc_struct(ctx, epub_chapter);
 	ch->path = fz_strdup(ctx, path);
@@ -316,7 +315,7 @@ epub_parse_ncx(fz_context *ctx, epub_document *doc, const char *path)
 	fz_dirname(base_uri, path, sizeof base_uri);
 
 	buf = fz_read_archive_entry(ctx, zip, path);
-	fz_write_buffer_byte(ctx, buf, 0);
+	fz_terminate_buffer(ctx, buf);
 	len = fz_buffer_storage(ctx, buf, &data);
 	ncx = fz_parse_xml(ctx, data, len, 0);
 	fz_drop_buffer(ctx, buf);
@@ -359,7 +358,7 @@ epub_parse_header(fz_context *ctx, epub_document *doc)
 	/* parse META-INF/container.xml to find OPF */
 
 	buf = fz_read_archive_entry(ctx, zip, "META-INF/container.xml");
-	fz_write_buffer_byte(ctx, buf, 0);
+	fz_terminate_buffer(ctx, buf);
 	len = fz_buffer_storage(ctx, buf, &data);
 	container_xml = fz_parse_xml(ctx, data, len, 0);
 	fz_drop_buffer(ctx, buf);
@@ -376,7 +375,7 @@ epub_parse_header(fz_context *ctx, epub_document *doc)
 	/* parse OPF to find NCX and spine */
 
 	buf = fz_read_archive_entry(ctx, zip, full_path);
-	fz_write_buffer_byte(ctx, buf, 0);
+	fz_terminate_buffer(ctx, buf);
 	len = fz_buffer_storage(ctx, buf, &data);
 	content_opf = fz_parse_xml(ctx, data, len, 0);
 	fz_drop_buffer(ctx, buf);
diff --git a/source/html/html-doc.c b/source/html/html-doc.c
index 05a86d83..c19d5049 100644
--- a/source/html/html-doc.c
+++ b/source/html/html-doc.c
@@ -139,12 +139,8 @@ htdoc_open_document_with_stream(fz_context *ctx, fz_stream *file)
 	doc->set = fz_new_html_font_set(ctx);
 
 	buf = fz_read_all(ctx, file, 0);
-
 	fz_try(ctx)
-	{
-		fz_write_buffer_byte(ctx, buf, 0);
 		doc->html = fz_parse_html(ctx, doc->set, doc->zip, ".", buf, fz_user_css(ctx));
-	}
 	fz_always(ctx)
 		fz_drop_buffer(ctx, buf);
 	fz_catch(ctx)
@@ -175,12 +171,8 @@ htdoc_open_document(fz_context *ctx, const char *filename)
 	doc->set = fz_new_html_font_set(ctx);
 
 	buf = fz_read_file(ctx, filename);
-
 	fz_try(ctx)
-	{
-		fz_write_buffer_byte(ctx, buf, 0);
 		doc->html = fz_parse_html(ctx, doc->set, doc->zip, ".", buf, fz_user_css(ctx));
-	}
 	fz_always(ctx)
 		fz_drop_buffer(ctx, buf);
 	fz_catch(ctx)
diff --git a/source/html/html-layout.c b/source/html/html-layout.c
index 91297f10..ff2102d1 100644
--- a/source/html/html-layout.c
+++ b/source/html/html-layout.c
@@ -406,10 +406,7 @@ static fz_image *load_html_image(fz_context *ctx, fz_archive *zip, const char *b
 		buf = fz_read_archive_entry(ctx, zip, path);
 #if FZ_ENABLE_SVG
 		if (strstr(path, ".svg"))
-		{
-			fz_write_buffer_byte(ctx, buf, 0);
 			img = fz_new_image_from_svg(ctx, buf);
-		}
 		else
 #endif
 			img = fz_new_image_from_buffer(ctx, buf);
@@ -2552,7 +2549,7 @@ fz_parse_html(fz_context *ctx, fz_html_font_set *set, fz_archive *zip, const cha
 	fz_xml *xml;
 	fz_html *html;
 	unsigned char *data;
-	size_t len = fz_buffer_storage(ctx, buf, &data);
+	size_t len;
 
 	fz_css_match match;
 	struct genstate g;
@@ -2565,6 +2562,8 @@ fz_parse_html(fz_context *ctx, fz_html_font_set *set, fz_archive *zip, const cha
 	g.emit_white = 0;
 	g.last_brk_cls = UCDN_LINEBREAK_CLASS_OP;
 
+	fz_terminate_buffer(ctx, buf);
+	len = fz_buffer_storage(ctx, buf, &data);
 	xml = fz_parse_xml(ctx, data, len, 1);
 
 	g.css = fz_new_css(ctx);
diff --git a/source/svg/svg-doc.c b/source/svg/svg-doc.c
index d0ff1e4a..06de56f5 100644
--- a/source/svg/svg-doc.c
+++ b/source/svg/svg-doc.c
@@ -91,6 +91,7 @@ svg_open_document_with_buffer(fz_context *ctx, fz_buffer *buf)
 	size_t len;
 	unsigned char *data;
 
+	fz_terminate_buffer(ctx, buf);
 	len = fz_buffer_storage(ctx, buf, &data);
 	root = fz_parse_xml(ctx, data, len, 0);
 
@@ -115,10 +116,7 @@ svg_open_document_with_stream(fz_context *ctx, fz_stream *file)
 
 	buf = fz_read_all(ctx, file, 0);
 	fz_try(ctx)
-	{
-		fz_write_buffer_byte(ctx, buf, 0);
 		doc = svg_open_document_with_buffer(ctx, buf);
-	}
 	fz_always(ctx)
 		fz_drop_buffer(ctx, buf);
 	fz_catch(ctx)
diff --git a/source/xps/xps-zip.c b/source/xps/xps-zip.c
index 53ea15f9..fe1dcce8 100644
--- a/source/xps/xps-zip.c
+++ b/source/xps/xps-zip.c
@@ -92,11 +92,8 @@ xps_read_part(fz_context *ctx, xps_document *doc, char *partname)
 		}
 	}
 
-	fz_write_buffer_byte(ctx, buf, 0); /* zero-terminate */
-
-	/* take over the data */
-	/* size doesn't include the added zero-terminator */
-	size = fz_buffer_extract(ctx, buf, &data) - 1;
+	fz_terminate_buffer(ctx, buf); /* zero-terminate */
+	size = fz_buffer_extract(ctx, buf, &data); /* take over the data ('size' excludes the zero terminator) */
 	fz_drop_buffer(ctx, buf);
 
 	return xps_new_part(ctx, doc, partname, data, size);