[Dev-C++] Please spot out the cause of this bug

[Curious S. <est...@re...>]

I am writing a program that will take a string that has a C source file and=
 it would format all the multi-line comments like these:=0A=0A=0A//Jingle b=
ells, jingle bells, jingles all the way=0A//O what fun it is to ride in a o=
ne-horse open sledge=0A//yeah, jingle bells....=0A=0A=0Ainto=0A=0A=0A/*Jing=
le bells, jingle bells, jingles all the way=0AO what fun it is to ride in a=
 one-horse open sledge=0Ayeah, jingle bells....*/=0A=0A=0Aor the lines,=0A=
=0A=0Ai=3D0; //Isn't it nice=0A//today? hehehehe....=0A=0A=0Ainto=0A=0A=0Ai=
=3D0; /*Isn't it nice=0Atoday? hehehehe...*/=0A=0A=0AThe code can be downlo=
aded from here. =0A=0Ahttp://www.vbforums.com/attachment.php?s=3D&postid=3D=
1841801=0A=0AI've finished coding it but I'm still not through debugging it=
.=0A=0AI've taken a linked list to represent a single comment block that ne=
eds to be formatted. Each node would represent one line of source code that=
 contains a comment.  The list is represented by a struct LOC that looks li=
ke this:=0A=0A=0A/*Represent a line of code that has a // comment in it=0AT=
he purpose of this structure is to store those lines of=0Asource code that:=
=0A=0A  (1) Contain a // in them=0A  (2) Appear in a series=0A  (3) Are a p=
art of one multi-line comment that is to be formatted=0A=0A  For more infor=
mation, please read the "Comments to be targetted" section=0A  in the speci=
fication file "Read Me.txt" in this project=0A*/=0Astruct LOC=0A{=0A    cha=
r *Text; //Text of the line containing the comment=0A=0A    struct LOC *Nex=
tLine; //Pointer to the next comment=0A=0A    int Len; //length of the line=
 containing the comment=0A=0A    int Position; //Starting position of the c=
omment in the line of text=0A=0A    int WasFirstNonSpaceChar; /*A boolean v=
alue indicating if the comment =0A                              was the fir=
st non-space character in the line =0A                              of text=
*/=0A};=0A=0A=0AI'm facing a problem in my FormatBlock function. Particular=
ly in this while loop within the FormatBlock function.=0A=0A=0A=0Awhile(hea=
d!=3DNULL)=0A    {=0A        if(strcat(NewBlock, Replace(head->Text, head->=
Position, head->Position+1, "  "))=3D=3DNULL)=0A            return NULL;=0A=
        =0A        if(head->NextLine=3D=3DNULL)=0A            strcat(NewBlo=
ck, "*/");=0A        else=0A            strcat(NewBlock, sNewLine);=0A     =
   head=3Dhead->NextLine;=0A    }=0A=0A=0A=0AWhat happens is that in this w=
hile loop, somehow, while i'm only traversing the loop and replacing, say, =
node 3 out of 5 nodes in my linked list, the text of the 5th node in the li=
st gets changed somehow. Just before this loop, all the elements are intact=
. I put printf statements at many steps and discovered that the problem is =
only when it comes to the 2nd element of the linked list within this loop t=
hat it changes the 5th element.=0A=0AFor a test, I am currently reading the=
 comments from a file that I created called "Code.c" and put in C:.=0A=0AYo=
u will find the file Code.c also within the attachment linked above. Please=
 download it and put the Code.c file in C: and then walk through the code.=
=0A=0A=0AThoughts as to what might be causing this problem? =0A=0A=0A=0APS:=
 I know there's a memory leak here in this line.=0A=0Aif(strcat(NewBlock, R=
eplace(head->Text, head->Position, head->Position+1, "  "))=3D=3DNULL)=0A=
=0AThis is just rough work. I have a day job, and I wrote that code in a hu=
rry. I will remove all leaks. Also the naming convention sucks because I ha=
ven't found a convention to stick to, that is to my taste. I still have to =
land on one. No typedef used instead of struct LOC* all the time.=20