ctx: Also check ferror(stdout)

Previously this was checked for all other files, but for stdout we just
checked the return value of fflush().  Checking ferror() makes sure we
don't miss any errors that occurred on a previous flush.

1 files changed, 27 insertions, 15 deletions

diff --git a/ctx.c b/ctx.c
index c86e41d..7f4fa03 100644
--- a/ctx.c
+++ b/ctx.c
@@ -1,6 +1,6 @@
 /****************************************************************************
  * bfs                                                                      *
- * Copyright (C) 2015-2021 Tavian Barnes <tavianator@tavianator.com>        *
+ * Copyright (C) 2015-2022 Tavian Barnes <tavianator@tavianator.com>        *
  *                                                                          *
  * Permission to use, copy, modify, and/or distribute this software for any *
  * purpose with or without fee is hereby granted.                           *
@@ -193,6 +193,22 @@ CFILE *bfs_ctx_dedup(struct bfs_ctx *ctx, CFILE *cfile, const char *path) {
 	return cfile;
 }
 
+/** Flush a file and report any errors. */
+static int bfs_ctx_flush(CFILE *cfile) {
+	int ret = 0, error = 0;
+	if (ferror(cfile->file)) {
+		ret = -1;
+		error = EIO;
+	}
+	if (fflush(cfile->file) != 0) {
+		ret = -1;
+		error = errno;
+	}
+
+	errno = error;
+	return ret;
+}
+
 /** Close a file tracked by the bfs context. */
 static int bfs_ctx_close(struct bfs_ctx *ctx, struct bfs_ctx_file *ctx_file) {
 	CFILE *cfile = ctx_file->cfile;
@@ -200,10 +216,14 @@ static int bfs_ctx_close(struct bfs_ctx *ctx, struct bfs_ctx_file *ctx_file) {
 	if (cfile == ctx->cout) {
 		// Will be checked later
 		return 0;
-	} else if (cfile == ctx->cerr && !ctx_file->path) {
+	} else if (cfile == ctx->cerr) {
 		// Writes to stderr are allowed to fail silently, unless the same file was used by
 		// -fprint, -fls, etc.
-		return 0;
+		if (ctx_file->path) {
+			return bfs_ctx_flush(cfile);
+		} else {
+			return 0;
+		}
 	}
 
 	int ret = 0, error = 0;
@@ -211,17 +231,9 @@ static int bfs_ctx_close(struct bfs_ctx *ctx, struct bfs_ctx_file *ctx_file) {
 		ret = -1;
 		error = EIO;
 	}
-
-	if (cfile == ctx->cerr) {
-		if (fflush(cfile->file) != 0) {
-			ret = -1;
-			error = errno;
-		}
-	} else {
-		if (cfclose(cfile) != 0) {
-			ret = -1;
-			error = errno;
-		}
+	if (cfclose(cfile) != 0) {
+		ret = -1;
+		error = errno;
 	}
 
 	errno = error;
@@ -259,7 +271,7 @@ int bfs_ctx_free(struct bfs_ctx *ctx) {
 		}
 		trie_destroy(&ctx->files);
 
-		if (cout && fflush(cout->file) != 0) {
+		if (cout && bfs_ctx_flush(cout) != 0) {
 			if (cerr) {
 				bfs_error(ctx, "standard output: %m.\n");
 			}