Add additional error checking to helpers.

core/image/png/helpers.odin

@@ -34,15 +34,17 @@ destroy :: proc(img: ^Image) {
 	}
 
 	bytes.buffer_destroy(&img.pixels)
+
+	assert(img.metadata_ptr != nil && img.metadata_type == Info)
+	v := (^Info)(img.metadata_ptr)
+
+	for chunk in &v.chunks {
+		delete(chunk.data)
+	}
+	delete(v.chunks)
+
 	// Clean up Info.
 	free(img.metadata_ptr)
-
-	/*
-		We don't need to do anything for the individual chunks.
-		They're allocated on the temp allocator, as is info.chunks
-
-		See read_chunk.
-	*/
 	free(img)
 }
 
@@ -50,46 +52,50 @@ destroy :: proc(img: ^Image) {
 	Chunk helpers
 */
 
-gamma :: proc(c: Chunk) -> f32 {
-	assert(c.header.type == .gAMA)
-	res := (^gAMA)(raw_data(c.data))^
-	when true {
-		// Returns the wrong result on old backend
-		// Fixed for -llvm-api
-		return f32(res.gamma_100k) / 100_000.0
-	} else {
-		return f32(u32(res.gamma_100k)) / 100_000.0
+gamma :: proc(c: Chunk) -> (res: f32, ok: bool) {
+	if c.header.type != .gAMA || len(c.data) != size_of(gAMA) {
+		return {}, false
 	}
+	gama := (^gAMA)(raw_data(c.data))^
+	return f32(gama.gamma_100k) / 100_000.0, true
 }
 
 INCHES_PER_METER :: 1000.0 / 25.4
 
-phys :: proc(c: Chunk) -> pHYs {
-	assert(c.header.type == .pHYs)
-	res := (^pHYs)(raw_data(c.data))^
-	return res
+phys :: proc(c: Chunk) -> (res: pHYs, ok: bool) {
+	if c.header.type != .pHYs || len(c.data) != size_of(pHYs) {
+		return {}, false
+	}
+
+	return (^pHYs)(raw_data(c.data))^, true 
 }
 
 phys_to_dpi :: proc(p: pHYs) -> (x_dpi, y_dpi: f32) {
 	return f32(p.ppu_x) / INCHES_PER_METER, f32(p.ppu_y) / INCHES_PER_METER
 }
 
-time :: proc(c: Chunk) -> tIME {
-	assert(c.header.type == .tIME)
-	res := (^tIME)(raw_data(c.data))^
-	return res
+time :: proc(c: Chunk) -> (res: tIME, ok: bool) {
+	if c.header.type != .tIME || len(c.data) != size_of(tIME) {
+		return {}, false
+	}
+
+	return (^tIME)(raw_data(c.data))^, true
 }
 
 core_time :: proc(c: Chunk) -> (t: coretime.Time, ok: bool) {
-	png_time := time(c)
-	using png_time
-	return coretime.datetime_to_time(
-		int(year), int(month), int(day),
-		int(hour), int(minute), int(second),
-	)
+	if png_time, png_ok := time(c); png_ok {
+		using png_time
+		return coretime.datetime_to_time(
+			int(year), int(month), int(day),
+			int(hour), int(minute), int(second),
+		)
+	} else {
+		return {}, false
+	}
 }
 
 text :: proc(c: Chunk) -> (res: Text, ok: bool) {
+	assert(len(c.data) == int(c.header.length))
 	#partial switch c.header.type {
 	case .tEXt:
 		ok = true
@@ -228,9 +234,7 @@ iccp_destroy :: proc(i: iCCP) {
 }
 
 srgb :: proc(c: Chunk) -> (res: sRGB, ok: bool) {
-	ok = true
-
-	if c.header.type != .sRGB || len(c.data) != 1 {
+	if c.header.type != .sRGB || len(c.data) != size_of(sRGB_Rendering_Intent) {
 		return {}, false
 	}
 
@@ -238,7 +242,7 @@ srgb :: proc(c: Chunk) -> (res: sRGB, ok: bool) {
 	if res.intent > max(sRGB_Rendering_Intent) {
 		ok = false; return
 	}
-	return
+	return res, true
 }
 
 plte :: proc(c: Chunk) -> (res: PLTE, ok: bool) {