Copy files until EOF, not the reported file size, to deal with bad sizes in

the proc filesystem.

1 files changed, 35 insertions, 27 deletions

diff --git a/libbb/copy_file_chunk.c b/libbb/copy_file_chunk.c
index e9663c354..c440a6102 100644
--- a/libbb/copy_file_chunk.c
+++ b/libbb/copy_file_chunk.c
@@ -29,38 +29,46 @@
 #include <sys/stat.h>
 #include "libbb.h"
 
-/*
- * Copy chunksize bytes between two file descriptors
- *
- * unsigned long is used so that if -1 is passed as chunksize it will read as
- * much as possible, and it will work with off_t or off64_t
- */
+/* Copy CHUNKSIZE bytes (or until EOF if CHUNKSIZE equals -1) from SRC_FILE
+ * to DST_FILE.  */
 extern int copy_file_chunk(FILE *src_file, FILE *dst_file, unsigned long long chunksize)
 {
-        off_t size, amount_written;
-        char buffer[BUFSIZ]; /* BUFSIZ is declared in stdio.h */
-        
-        while (chunksize > 0) {
-                if (chunksize > BUFSIZ) {
+        size_t nread, nwritten, size;
+        char buffer[BUFSIZ];
+
+        while (chunksize != 0) {
+                if (chunksize > BUFSIZ)
                         size = BUFSIZ;
-                } else {
+                else
                         size = chunksize;
+
+                nread = fread (buffer, 1, size, src_file);
+
+                if (nread != size && ferror (src_file)) {
+                        perror_msg ("read");
+                        return -1;
+                } else if (nread == 0) {
+                        if (chunksize != -1) {
+                                error_msg ("Unable to read all data");
+                                return -1;
+                        }
+
+                        return 0;
                 }
-                amount_written = fwrite(buffer, 1, fread(buffer, 1, size, src_file), dst_file);
-                if (amount_written != size) {
-                        error_msg("Couldnt write correct amount");
-                        return(FALSE);
+
+                nwritten = fwrite (buffer, 1, nread, dst_file);
+
+                if (nwritten != nread) {
+                        if (ferror (dst_file))
+                                perror_msg ("write");
+                        else
+                                error_msg ("Unable to write all data");
+                        return -1;
                 }
-                chunksize -= amount_written;
+
+                if (chunksize != -1)
+                        chunksize -= nwritten;
         }
-        return (TRUE);
-}
 
-/* END CODE */
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/
+        return 0;
+}