[patch] -Wcast-qual cleanup

[and]

most (but not all) -Wcast-qual cleanup.

By -Wcast-qual flag compiler warns when const declaration is violated.

[andrew_b]

Ok, no try to find and fix memory allocations introduced in these patches.

[zaytsev]

I think it would be great to get the const-correctness fixed, but one needs to inspect what the callers & callees are doing very carefully, sometimes adapting the return types and sometimes the interface, but simply replacing const_casts with g_strdup is not a solution.

I've just looked at the few first and few last patches, and while many look okay and safe, the strutil* changes definitively feel wrong, just as the skin_name_default stuff, etc.

@and, re. mc-3598-0033-subshell-common.c-cleanup-Wcast-qual-warning.patch:

See an example here on how to use this function correctly without causing memory leaks:

​http://pubs.opengroup.org/onlinepubs/9699919799/functions/putenv.html

In the particular case of putenv(), there is an alternative called setenv(), but probably we don't want to switch to it (I'm not sure of the implementation status).

Same approach can be used at all places where you replace constants with heap allocated strings, but for some reason you can't add const qualifier to the function interface.

However, this should be an exception rather than the rule.

[and]

I have created patches per file, so you can pick/ACK or NAK per file easily.
Remaining patches are a basis for discussion and yes I not free of errors.

Lets take this for example from
mc-3598-0033-subshell-common.c-cleanup-Wcast-qual-warning.patch:

-    return (case_sen) ? (char *) text : str_8bit_strdown (text);
+    return (case_sen) ? g_strdup (text) : str_8bit_strdown (text);

str_8bit_strdown() will already return a s_strdup'ed value,
so by should be g_strdup(text) false?

By the way I found a compile warning introduction when dealing without XDG support, patch updated.

[andrew_b]

Replying to and:

-    return (case_sen) ? (char *) text : str_8bit_strdown (text);
+    return (case_sen) ? g_strdup (text) : str_8bit_strdown (text);

str_8bit_strdown() will already return a s_strdup'ed value,
so by should be g_strdup(text) false?

Because

    if (!case_sen)
        g_free (key);

[and]

ups, questionable strutil* patches with g_strdup() parts updated

[andrew_b]

Replying to and:

ups, questionable strutil* patches with g_strdup() parts updated

I don't like string duplication. If we can do without that we should.

[andrew_b]

Branch: 3598_wcast_qual.
Initial changeset:f2ea9630614d20212eaaaa7aaec388025d06f34b

mc-3598-0000-widget-common-introduce-CWIDGET-helper.patch​: applied with rename CWIDGET -> CONST_WIDGET.
mc-3598-0001-widget-common.c-cleanup-Wcast-qual-warning.patch​: applied.
mc-3598-0002-filemanager-panel.c-cleanup-Wcast-qual-warning.patch​: applied.
mc-3598-0003-filemanager-boxes.c-cleanup-Wcast-qual-warning.patch​: not applied yet.
mc-3598-0004-paths.c-cleanup-Wcast-qual-warning.patch: applied.
mc-3598-0005-search-lib.c-cleanup-Wcast-qual-warning.patch​: applied.
mc-3598-0006-search-regex.c-cleanup-Wcast-qual-warning.patch​: applied.
mc-3598-0007-skin-ini-file.c-cleanup-Wcast-qual-warning.patch​: applied.
mc-3598-0008-tty-key.c-cleanup-Wcast-qual-warning.patch: applied.
mc-3598-0009-tty-tty-ncurses.c-cleanup-Wcast-qual-warning.patch: applied.
mc-3598-0010-vfs-path.c-cleanup-some-Wcast-qual-warning.patch: applied.

Other patches will be reviewed later.

[andrew_b]

mc-3598-0011-widget-dialog.c-cleanup-Wcast-qual-warning.patch: applied.
mc-3598-0012-widget-input.c-cleanup-Wcast-qual-warning.patch: not applied because of different fix.
mc-3598-0013-widget-input_complete.c-cleanup-Wcast-qual-warning.patch: applied.
mc-3598-0014-widget-quick.c-cleanup-Wcast-qual-warning.patch: not applied yet.
mc-3598-0015-utilunix.c-cleanup-Wcast-qual-warning.patch: skipped because of extra string duplication.
mc-3598-0016-filemanager-file.c-cleanup-Wcast-qual-warning.patch: applied with some modification (like of patch 0012).
mc-3598-0017-filemanager-find.c-cleanup-Wcast-qual-warning.patch: applied partially because of extra string duplication. Another fix is required.
mc-3598-0018-extfs.c-cleanup-Wcast-qual-warning.patch: applied.
mc-3598-0019-viewer-dialogs.c-cleanup-Wcast-qual-warning.patch: not applied yet.
mc-3598-0020-viewer-search.c-cleanup-some-Wcast-qual-warning.patch: applied.
mc-3598-0021-editor-choosesyntax.c-cleanup-Wcast-qual-warning.patch: applied.

Other patches will be reviewed later.

[andrew_b]

mc-3598-0022-editor-editcmd.c-cleanup-some-Wcast-qual-warning.patch: applied.
mc-3598-0023-editor-edit_dialogs.c-cleanup-Wcast-qual-warning.patch: applied partially.
mc-3598-0024-editor-editdraw.c-cleanup-Wcast-qual-warning.patch: applied.
mc-3598-0025-editor-syntax.c-cleanup-Wcast-qual-warning.patch: applied.
mc-3598-0026-diffviewer-search.c-cleanup-Wcast-qual-warning.patch: not applied yet.
mc-3598-0027-diffviewer-ydiff.c-cleanup-Wcast-qual-warning.patch: applied partially with another fix.
mc-3598-0028-clipboard.c-cleanup-Wcast-qual-warning.patch: applied.
mc-3598-0029-widget-buttonbar.c-cleanup-Wcast-qual-warning.patch: applied.
mc-3598-0030-filemanager-layout.c-cleanup-Wcast-qual-warning.patch: skipped because of extra string duplication.
mc-3598-0031-setup.c-cleanup-Wcast-qual-warning.patch: applied.
mc-3598-0032-execute.c-cleanup-Wcast-qual-warning.patch: skipped because of extra string duplication.
mc-3598-0033-subshell-common.c-cleanup-Wcast-qual-warning.patch: skipped because of unneeded string duplication.
mc-3598-0034-strutil-strutil8bit.c-cleanup-Wcast-qual-warning.patch: skipped because of unneeded string duplication.
mc-3598-0035-strutil-strutilascii.c-cleanup-Wcast-qual-warning.patch: skipped because of unneeded string duplication.
mc-3598-0036-strutil-strutilutf8.c-cleanup-some-Wcast-qual-warnings.patch: skipped because of unneeded string duplication.

[andrew_b]

Changesets are reodered.

Branch: 3598_wcast_qual.
Initial changeset:767287c9d2e15e25bb7e5c64fff4e9322d6b95ba

I thing this is enough for first iteration. Please review.

[andrew_b]

Merged to master: [9d0f6e584ef86daeb421a5d63898ee2effe8f5d8].

git log --pretty=oneline 51d0783..9d0f6e5