A few general utility functions added for the sake of the forms work

3 files changed, 23 insertions, 1 deletions

diff --git a/fitz/fitz-internal.h b/fitz/fitz-internal.h
index 05d7b52f..2f7f8041 100644
--- a/fitz/fitz-internal.h
+++ b/fitz/fitz-internal.h
@@ -419,6 +419,13 @@ void fz_write_buffer_bits(fz_context *ctx, fz_buffer *buf, int val, int bits);
 
 void fz_write_buffer_pad(fz_context *ctx, fz_buffer *buf);
 
+/*
+	fz_buffer_printf: print formatted to a buffer. The buffer will
+	grow, but the caller must ensure that no more than 256 bytes are
+	added to the buffer per call.
+*/
+void fz_buffer_printf(fz_context *ctx, fz_buffer *buffer, char *fmt, ...);
+
 struct fz_stream_s
 {
 	fz_context *ctx;
diff --git a/fitz/fitz.h b/fitz/fitz.h
index ee00b2ed..a66976af 100644
--- a/fitz/fitz.h
+++ b/fitz/fitz.h
@@ -403,7 +403,7 @@ void *fz_calloc(fz_context *ctx, unsigned int count, unsigned int size);
 	exception on failure to allocate.
 */
 #define fz_malloc_struct(CTX, STRUCT) \
-	Memento_label(fz_calloc(CTX,1,sizeof(STRUCT)), #STRUCT)
+	((STRUCT *)Memento_label(fz_calloc(CTX,1,sizeof(STRUCT)), #STRUCT))
 
 /*
 	fz_malloc_array: Allocate a block of (non zeroed) memory (with
diff --git a/fitz/stm_buffer.c b/fitz/stm_buffer.c
index 58539bf8..d14b738f 100644
--- a/fitz/stm_buffer.c
+++ b/fitz/stm_buffer.c
@@ -159,3 +159,18 @@ void fz_write_buffer_pad(fz_context *ctx, fz_buffer *buf)
 {
 	buf->unused_bits = 0;
 }
+
+void
+fz_buffer_printf(fz_context *ctx, fz_buffer *buffer, char *fmt, ...)
+{
+	va_list args;
+	va_start(args, fmt);
+
+	/* Caller guarantees not to generate more than 256 bytes per call */
+	while(buffer->cap - buffer->len < 256)
+		fz_grow_buffer(ctx, buffer);
+
+	buffer->len += vsprintf(buffer->data + buffer->len, fmt, args);
+
+	va_end(args);
+}