i'm confused as to why these fields exist, since the typical
implementation of a "temporary alloc" would be something like alloca(),
and alloca() is usually just inlined code that adjusts the stack
pointer, which is not a function whose address could be taken.

this breaks the API/ABI and will require a note in the ChangeLog.

possibly we could revisit the idea of "temporary allocations" by using
C99 variable length arrays. this would have the advantage of being
standardized, unlike alloca().

this should silence Coverity #1153648, which complains because
tmp.length_prefix_len is uninitialized for certain wire types when
copied on line 2486:

    scanned_member_slabs[which_slab][in_slab_index++] = tmp;

dave's original style drives me crazy. reformat the C code in
protobuf-c/ with "indent -kr -i8" and manually reflow for readability.

try to fit most lines in 80 columns, but due to the lengthy type and
function names in protobuf-c, enforcing an 80 column rule would result
in a lot of cramped statements, so try to fit lines in up to 100 columns
if it would improve readability. (e.g., one <=100 column line is
probably better than 3-4 <=80 column lines.)

ultimately i'd like to adopt most of the recommendations in the linux
coding style: https://www.kernel.org/doc/Documentation/CodingStyle.
this commit gets us most of the kernel indentation and comment coding
style recommendations. later commits will tackle style recommendations
that require more intrusive changes: breaking up large functions,
replacing macros that affect control flow (e.g., DO_ALLOC). this will
hopefully facilitate review and make the code base easier to maintain.

i ran the old and new versions of protobuf-c.c through something like:

  gcc -S -D__PRETTY_FUNCTION__=0 -D__FILE__=0 -D__LINE__=0 -Wall -O0 \
    -o protobuf-c.S -c protobuf-c.c

and reviewed the diffs of the assembly output to spot any functions that
changed, and went back to make sure that any differences were
functionally equivalent.

(fixes #26)

(fixes #106)

protoc-c/c_enum.cc: fix compiler warnings
protoc-c/c_field.cc: fix compiler warnings

Signed-off-by: Dave Benson <lahiker42@gmail.com>

better compatibility with 8- and 16-bit platforms (integrate fixes
from #47)

protobuf_c_dispatch_close_fd() (fixes #82)

check for server closures (responses) to not crash the server in case of
a malformed message (related to #76)

protobuf_c_message_check

leave a dangling pointer to the parsed submessage

test_field_merge

of the same field on the wire (Fixes #91)
t/generated-code2/test-generated-code2.c: add a test case for merging
messages
t/test-full.proto: expand message definitions to test for merging nested
messages

this simplifies the AC_C_BIGENDIAN invocation.