m.nviz.image: Fix Resource Leak issue

[ShubhamDesai]

This pull request fixes issue identified by Coverity Scan (CID : 1207735, 1207736, 1207924, 1207925, 1208025, 1208026, 1208027, 1208028, 1208029, 1400466, 1501205, 1501280, 1501338)
Used G_free() to fix this issue.

[nilason]

There are a number of similar issues in m.nviz.image, please filter with misc/m.nviz.image/*, to address them all (they all seem to be uncomplicated).

[ShubhamDesai]

There are a number of similar issues in m.nviz.image, please filter with misc/m.nviz.image/*, to address them all (they all seem to be uncomplicated).

done all changes

[nilason]

All calls to G_fully_qualified_name() returns an allocated value which must be freed.

[ShubhamDesai]

All calls to G_fully_qualified_name() returns an allocated value which must be freed.

done

[ShubhamDesai]

All calls to G_fully_qualified_name() returns an allocated value which must be freed.

is there anything wrong in code? mac build failed.
I would fix the clang formatting issues sorry about the noise.

[nilason]

I added a few suggestions.

[nilason]

Instead of re-declare mname, you can do it once here (with initialisation): char *mname = NULL.

[ShubhamDesai]

done

[nilason]

This is what is causing the Mac runner to fail:

error: variable 'column' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
  307 |     if (Fi) {
      |         ^~
vector.c:361:20: note: uninitialized use occurs here
  361 |     db_free_column(column);
      |                    ^~~~~~
vector.c:307:5: note: remove the 'if' if its condition is always true
  307 |     if (Fi) {
      |     ^~~~~~~
vector.c:261:21: note: initialize the variable 'column' to silence this warning
  261 |     dbColumn *column;
      |                     ^
      |                      = NULL
1 error generated.

you should move Vect_destroy_field_info(Fi); to the end of the if (Fi) statement (before or after db_close_database_shutdown_driver(driver);).

column is allocated with db_get_column() four times, and should be freed after each use (by db_column_Ctype()).

[ShubhamDesai]

done

[nilason]

You may move declaration (and initialisation) of int layer = -1, with_z = 0 to the beginning of the for (i = 0; i < nsites; i++) { statement (L184). They are set in every loop with check_map(), and should be zeroed before.

(There is a bug in check_map(), L291: if (with_z) *with_z = Vect_is_3d(&Map);. The with_z is however an out parameter, thus checking it does not make any sense. That is out of scope of this PR anyway).

[ShubhamDesai]

done