Prevent crashes and leaks on allocation failure (#606)

* Prevent crashes and leaks on allocation failure

Memory allocation can fail. We need to gracefully handle this case and
prevent dereferencing null pointers.

* Make NULL checks consistent within a file

* Properly report allocation errors

* Improve cleanup in pj_gc_reader.c

* Implement pj_strdup and use instead of strdup

The function strdup is not part of ANSI C 89, but a POSIX extension.
Therefore we can not rely on it being available on all platforms.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/pj_fileapi.c b/src/pj_fileapi.c
index 1e5bfa51..e223993e 100644
--- a/src/pj_fileapi.c
+++ b/src/pj_fileapi.c
@@ -26,6 +26,7 @@
  * DEALINGS IN THE SOFTWARE.
  *****************************************************************************/
 
+#include <errno.h>
 #include <projects.h>
 #include <string.h>
 
@@ -76,6 +77,13 @@ static PAFile pj_stdio_fopen(projCtx ctx, const char *filename,
     }
 
     pafile = (stdio_pafile *) malloc(sizeof(stdio_pafile));
+    if (!pafile)
+    {
+        pj_ctx_set_errno(ctx, ENOMEM);
+        fclose(fp);
+        return NULL;
+    }
+
     pafile->fp = fp;
     pafile->ctx = ctx;
     return (PAFile) pafile;