From 7521206b2945ef26ba1eb3d86f7e0d3fc4f92085 Mon Sep 17 00:00:00 2001
From: Cody Boone Ferguson <53008573+xexyl@users.noreply.github.com>
Date: Sun, 28 May 2023 12:33:53 -0700
Subject: [PATCH] Change infinite loop bug status in 1990/theorem

If one passes to the Fibonacci or theorem_bkp program 0 0 it enters an
infinite loop repeatedly printing 0. I think this is better to be just
documented and not fixed. Another condition where this occurred was
fixed but as I recall that might have affected usability and this one in
any event does not.
---
 1990/theorem/.gitignore |  1 +
 1990/theorem/README.md  | 25 +++++++++++++++--------
 bugs.md                 | 45 +++++------------------------------------
 3 files changed, 23 insertions(+), 48 deletions(-)

diff --git a/1990/theorem/.gitignore b/1990/theorem/.gitignore
index 12683bf7d..a9223bbb1 100644
--- a/1990/theorem/.gitignore
+++ b/1990/theorem/.gitignore
@@ -1,3 +1,4 @@
+theorem
 fibonacci
 fibonacci.c
 mariano
diff --git a/1990/theorem/README.md b/1990/theorem/README.md
index 4b6d753dc..ca82b074c 100644
--- a/1990/theorem/README.md
+++ b/1990/theorem/README.md
@@ -29,7 +29,7 @@ about `gets()` at linking or runtime. Thank you Cody for your assistance!
 
 [Yusuke Endoh](/winners.html#Yusuke_Endoh) pointed out that `atof` nowadays
 needs `#include <stdlib.h>` which was used in order to get this to work
-initially. Thank you Yusuke!
+initially (prior to this the output was incomplete). Thank you Yusuke!
 
 
 ## To run:
@@ -54,20 +54,29 @@ y1 - initial value  (y(x1) == y1)
 ./theorem y 0 1 0.1 1
 ```
 
-### Known bug with `fibonacci.c` and `theorem_bkp.c`:
+### INABIAF - it's not a bug it's a feature! :-)
 
-If the two args added up equals 0 the program will enter an infinite loop,
-printing 0 over and over again. Cody fixed another condition where this happens
-but this has not been fixed. See [bugs.md](/bugs.md) for more details.
+If the two args passed to `fibonacci` and `theorem_bkp` equals 0 it will
+print 0 over and over again in an infinite loop. In this case it should not be
+fixed (another condition where this occurred was fixed as it affected usability
+of the program).
+
+BTW: why can't the fix:
+
+```c
+if (a[1]==NULL||a[2]==NULL||a[3]==NULL||a[4]==NULL||a[5]==NULL) return 1;
+```
+
+be changed to just test the value of `A` when `a` is argv and `A` is argc?
 
 ## Judges' remarks:
 
 The program's source implements four functions, all from the
 same source file!
 
-When you compile theorem.c as is and run with 5 args, it numerically
-solves the equation `y'=f(x,y)`, with a step size of `h`, over the interval 
-`x=[x1,x2]`, with the initial condition of `y(x1)=y1`.
+When you compile theorem.c as is and run with 5 args, it numerically solves the
+equation `y'=f(x,y)`, with a step size of `h` (see above usage), over the
+interval `x=[x1,x2]`, with the initial condition of `y(x1)=y1`.
 
 The 'expression' `f(x,y)` is any function of `x` and `y` with the
 operators:
diff --git a/bugs.md b/bugs.md
index 9bf724424..a84117db6 100644
--- a/bugs.md
+++ b/bugs.md
@@ -596,48 +596,13 @@ so it should stay with this note.
 
 
 ## [1990/theorem](1990/theorem/theorem.c) ([README.md](1990/theorem/README.md))
-## STATUS: known bug - please help us fix
+## STATUS: INABIAF - please **DO NOT** fix
 
 [Cody Boone Ferguson](/winners.html#Cody_Boone_Ferguson) fixed many bugs that
-prevented this from working properly (including segfaults) but one bug known to
-exist remains: if `theorem_bkp` or `fibonacci` is passed two zeros the program
-will enter an infinite loop, printing 0 over and over again (another condition
-where this occurred was fixed).
-
-Cody provides some hints here:
-
-0. The function in `theorem.c` that matters is `w` (see below for definition).
-1. However adding checks for the value being > 0 does not work due to the way the
-code is generated. See below.
-
-`w()` looks like this:
-
-```c
-w(g,R,u)float*g,u;char R;
-/**/{int b,f;if(A>2){A=atoi(a[1]);b=atoi(a[2]);while((f=A+b)<15000){printf("%d\n",f);A=b;b=f;}}}
-```
-
-But as far as point 1 above changing it to be:
-
-```c
-/**/{int b,f;if(A>2){A=atoi(a[1]);b=atoi(a[2]);while(f!=0&&(f=A+b)<15000){printf("%d\n",f);A=b;b=f;}}}
-```
-
-and similar (like checking `>0`, doing a `do..while`, doing an `if` before the
-while etc.) cause compilation errors.
-
-Can you fix this? We welcome your help!
-
-BTW: one of the important fixes for `fibonacci` to work is:
-
-```diff
--/**/{int b,f;A=atoi(++a);b=atoi(++a);while((f=A+b)<15000){printf("%d\n",f);A=b;b=f;}}
-+/**/{int b,f;if(A>2){A=atoi(a[1]);b=atoi(a[2]);while((f=A+b)<15000){printf("%d\n",f);A=b;b=f;}}}
-```
-
-Observe the check for the number of args and the calls to `atoi()` have been
-changed a bit too.
-
+prevented this from working properly (including segfaults) but one thing to note
+is that if you pass two zeroes to `theorem_bkp` or `fibonacci` the program
+will enter an infinite loop, printing 0 over and over again; another condition
+where this occurred was fixed but this one should not be fixed. Thank you.
 
 ## [1990/westley](1990/westley/westley.c) ([README.md](1990/westley/README.md))
 ## STATUS: INABIAF - please **DO NOT** fix