Thanks Thorsten! A modified commit has been merged into the 'master' branch as Commit 0dd7bcc0f.

Please compare this commit with your original commit (the message and the changes in the code) for the future. Generally, I recommend to re-read the Gnuastro Coding Conventions (based on the GNU Coding conventions) and Commit guidelines.

Here is a summary of the main issues:

• There was no title in the commit message.
• The commit message paragraphs were not properly adjusted.
• The comments within the code should be written for the code after your change and should not refer to old behavior (as in "according to #63064 this is not the desired behaviour ..."). For any other contributor (other than you and me), the "this" is not clear!
• Have a look at other multi-line comments with the code, Gnuastro does not put a '*' at the start of such long comments.
• Use a single command to print warnings in one line. Also, don't use 'printf' because it does not show the user which program produced the error, use 'error(EXIT_SUCESS, 0, ...)'. This will allow the user to easily identify which program produced the error.
• Do not report a commit that is not yet working completely: as you mentioned it would crash when trying to print the histogram. This crash would return a non-zero value to the running shell, causing a crash in pipelines.

Until the bug is fixed, the following condition can be used in a script: we are using the shell's 'if' to check if Statistics returned successfully or not. If not, the script can be prepared to deal with scenarios where all the inputs are NaN.

$ if aststatistics img.fits; then echo GOOD; else echo BAD; fi