From f8606ebab87d2b20fa442769265f739958d94ca5 Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Fri, 12 Oct 2018 14:00:34 +0900
Subject: [PATCH] Fix a object file segfault when spaces have no data.

ie, don't attempt to copy memory from a null pointer (just copy the null
pointer).
---
 tools/qfcc/source/obj_file.c | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/tools/qfcc/source/obj_file.c b/tools/qfcc/source/obj_file.c
index cdd18f991..1ebd97f4b 100644
--- a/tools/qfcc/source/obj_file.c
+++ b/tools/qfcc/source/obj_file.c
@@ -193,8 +193,11 @@ qfo_init_string_space (qfo_t *qfo, qfo_mspace_t *space, strpool_t *strings)
 	space->type = qfos_string;
 	space->num_defs = 0;
 	space->defs = 0;
-	space->d.strings = malloc (size);
-	memcpy (space->d.strings, strings->strings, size);
+	space->d.strings = 0;
+	if (strings->strings) {
+		space->d.strings = malloc (size);
+		memcpy (space->d.strings, strings->strings, size);
+	}
 	space->data_size = strings->size;
 	space->id = qfo_strings_space;
 }
@@ -207,8 +210,11 @@ qfo_init_code_space (qfo_t *qfo, qfo_mspace_t *space, codespace_t *code)
 	space->type = qfos_code;
 	space->num_defs = 0;
 	space->defs = 0;
-	space->d.code = malloc (size);
-	memcpy (space->d.code, code->code, size);
+	space->d.code = 0;
+	if (code->code) {
+		space->d.code = malloc (size);
+		memcpy (space->d.code, code->code, size);
+	}
 	space->data_size = code->size;
 	space->id = qfo_code_space;
 }
@@ -222,8 +228,11 @@ qfo_init_data_space (qfo_t *qfo, qfo_def_t **defs, qfo_reloc_t **relocs,
 	space->type = qfos_data;
 	space->defs = *defs;
 	space->num_defs = qfo_encode_defs (qfo, data->defs, defs, relocs);
-	space->d.data = malloc (size);
-	memcpy (space->d.data, data->data, size);
+	space->d.data = 0;
+	if (data->data) {
+		space->d.data = malloc (size);
+		memcpy (space->d.data, data->data, size);
+	}
 	space->data_size = data->size;
 }
 
@@ -249,8 +258,11 @@ qfo_init_type_space (qfo_t *qfo, qfo_def_t **defs, qfo_reloc_t **relocs,
 	space->type = qfos_type;
 	space->defs = *defs;
 	space->num_defs = qfo_encode_defs (qfo, data->defs, defs, relocs);
-	space->d.data = malloc (size);
-	memcpy (space->d.data, data->data, size);
+	space->d.data = 0;
+	if (data->data) {
+		space->d.data = malloc (size);
+		memcpy (space->d.data, data->data, size);
+	}
 	space->data_size = data->size;
 	space->id = qfo_type_space;
 }