RFC Compile cleanly in pedantic mode

While developing 6aaded550 ("builtin/config: work around an unsized array forward declaration", 2018-07-05), I have compiled Git with CFLAGS="-std=c99 -pedantic".

This is an RFC patch series that fixes a few compiler warnings when compiling with these options, always assuming that this is a worthwile goal.

Note that all warnings were produced by -pedantic; the C99 standard option by itself didn't cause any of them.

The warnings were:

1) Char arrays initialized from a parenthesized string.

Suppressed by defining USE_PARENS_AROUND_GETTEXT_N to 0 globally. This was done just to keep the amount of warnings manageable; this series leaves that knob alone. The advantage of not mistakenly concatenating two translated strings is greater.

2) connect.h, refs/refs-internal.h: Forward reference to an enum.

Added two #includes that define the enums. This was already (inconclusively) talked about in [0].

3) convert.c: Invalid escape sequence "\e".

        Replaced with "\033".

4) seqencer.c: Empty statements at top level.

Removed the extra semicolons.

5) string-list.c: Forbidden to cast from void * to a function pointer and vice versa.

Encapsulated the function pointer in a context struct. This is controversial because it has a performance impact, namely one additional pointer dereference per string comparison. An alternative might be to use multiple casts via intptr_t. But I'm not sure if this is worth the trouble.

6) utf8.c: overflow of char values.

Use unsigned char for the BOM constants.

This series has patches for 2) to 6).

Regards,
Beat

[0] https://public-inbox.org/git/[email protected]/T/