Add LZMA_RET_INTERNAL1..8 to lzma_ret and use one for LZMA_TIMED_OUT.

LZMA_TIMED_OUT is *internally* used as a value for lzma_ret
enumeration. Previously it was #defined to 32 and cast to lzma_ret.
That way it wasn't visible in the public API, but this was hackish.

Now the public API has eight LZMA_RET_INTERNALx members and
LZMA_TIMED_OUT is #defined to LZMA_RET_INTERNAL1. This way
the code is cleaner overall although the public API has a few
extra mysterious enum members.

src/liblzma/api/lzma/base.h

@@ -235,7 +235,7 @@ typedef enum {
 		 * how to report bugs.
 		 */
 
-	LZMA_SEEK_NEEDED        = 12
+	LZMA_SEEK_NEEDED        = 12,
 		/**<
 		 * \brief       Request to change the input file position
 		 *
@@ -251,6 +251,19 @@ typedef enum {
 		 * After seeking the application should read new input and
 		 * pass it normally via lzma_stream.next_in and .avail_in.
 		 */
+
+	/*
+	 * These eumerations may be used internally by liblzma
+	 * but they will never be returned to applications.
+	 */
+	LZMA_RET_INTERNAL1      = 101,
+	LZMA_RET_INTERNAL2      = 102,
+	LZMA_RET_INTERNAL3      = 103,
+	LZMA_RET_INTERNAL4      = 104,
+	LZMA_RET_INTERNAL5      = 105,
+	LZMA_RET_INTERNAL6      = 106,
+	LZMA_RET_INTERNAL7      = 107,
+	LZMA_RET_INTERNAL8      = 108
 } lzma_ret;
 
 

src/liblzma/common/common.c

@@ -298,9 +298,7 @@ lzma_code(lzma_stream *strm, lzma_action action)
 
 	strm->internal->avail_in = strm->avail_in;
 
-	// Cast is needed to silence a warning about LZMA_TIMED_OUT, which
+	switch (ret) {
-	// isn't part of lzma_ret enumeration.
-	switch ((unsigned int)(ret)) {
 	case LZMA_OK:
 		// Don't return LZMA_BUF_ERROR when it happens the first time.
 		// This is to avoid returning LZMA_BUF_ERROR when avail_out

src/liblzma/common/common.h

@@ -83,9 +83,8 @@
 
 /// Special return value (lzma_ret) to indicate that a timeout was reached
 /// and lzma_code() must not return LZMA_BUF_ERROR. This is converted to
-/// LZMA_OK in lzma_code(). This is not in the lzma_ret enumeration because
+/// LZMA_OK in lzma_code().
-/// there's no need to have it in the public API.
+#define LZMA_TIMED_OUT LZMA_RET_INTERNAL1
-#define LZMA_TIMED_OUT 32
 
 
 typedef struct lzma_next_coder_s lzma_next_coder;

src/xz/message.c

@@ -833,6 +833,14 @@ message_strm(lzma_ret code)
 	case LZMA_GET_CHECK:
 	case LZMA_PROG_ERROR:
 	case LZMA_SEEK_NEEDED:
+	case LZMA_RET_INTERNAL1:
+	case LZMA_RET_INTERNAL2:
+	case LZMA_RET_INTERNAL3:
+	case LZMA_RET_INTERNAL4:
+	case LZMA_RET_INTERNAL5:
+	case LZMA_RET_INTERNAL6:
+	case LZMA_RET_INTERNAL7:
+	case LZMA_RET_INTERNAL8:
 		// Without "default", compiler will warn if new constants
 		// are added to lzma_ret, it is not too easy to forget to
 		// add the new constants to this function.