I tried to find it too, here's the "
CInput->ProcessInput()" function peudocode (0.3.7 R1 samp version):
	
	
	
		C++:
	
	
		void __fastcall CInput->ProcessInput_10065d30(int iParm1)
{
  char cVar1;
  undefined4 uVar2;
  code *pcVar3;
  char *pcVar4;
  char *pcVar5;
  char local_84 [132];
  char *szInputBuffer;
  char *2ndCharPointer;
  
  if (*(int *)(iParm1 + 8) == 0) {
    return;
  }
                    /* 0x14e4 = CInput->szInputBuffer[129] */
  szInputBuffer = (char *)(iParm1 + 0x14e4);
  uVar2 = FUN_10081030(0x80);
  FUN_100b6090(szInputBuffer,uVar2);
                    /* 0x1564 = last char of CInput->szInputBuffer[129] */
  *(undefined *)(iParm1 + 0x1564) = 0;
  2ndCharPointer = szInputBuffer;
  do {
    cVar1 = *2ndCharPointer;
    2ndCharPointer = 2ndCharPointer + 1;
  } while (cVar1 != '\0');
                    /* 0x14e4 = CInput->szInputBuffer[129]
                       so it's 2nd character */
  if (2ndCharPointer == (char *)(iParm1 + 0x14e5)) goto LAB_10065e74;
  CInput->AddRecall_10065930(szInputBuffer);
                    /* 0x1af0 = CInput->iCurrentRecall */
  *(undefined4 *)(iParm1 + 0x1af0) = 0xffffffff;
  if (*szInputBuffer != '/') {
                    /* 0x1af8 = CMDPROC CInput->pszDefaultCMD */
    if (*(code **)(iParm1 + 0x1af8) != (code *)0x0) {
      (**(code **)(iParm1 + 0x1af8))(szInputBuffer);
    }
    goto LAB_10065e62;
  }
                    /* 0x14e4 = CInput->szInputBuffer[129]
                       so it's 2nd character */
  2ndCharPointer = (char *)(iParm1 + 0x14e5);
  pcVar5 = 2ndCharPointer;
  if (*2ndCharPointer == '\0') {
LAB_10065dd4:
    pcVar3 = (code *)CInput->GetCommandHandler_10065a70(2ndCharPointer);
    if (pcVar3 == (code *)0x0) {
      if (DAT_1021a0f8 == 0) goto LAB_10065e58;
      SendCommandToServer_10065c60(szInputBuffer);
    }
    else {
      (*pcVar3)(&DAT_100d39c5);
    }
  }
  else {
    do {
      if (*pcVar5 == ' ') break;
      pcVar4 = pcVar5 + 1;
      pcVar5 = pcVar5 + 1;
    } while (*pcVar4 != '\0');
    if (*pcVar5 == '\0') goto LAB_10065dd4;
    pcVar4 = szInputBuffer;
    do {
      cVar1 = *pcVar4;
      pcVar4[(int)(local_84 + -(int)szInputBuffer)] = cVar1;
      pcVar4 = pcVar4 + 1;
    } while (cVar1 != '\0');
    *pcVar5 = '\0';
    pcVar3 = (code *)CInput->GetCommandHandler_10065a70(2ndCharPointer);
    if (pcVar3 == (code *)0x0) {
      if (DAT_1021a0f8 != 0) {
        SendCommandToServer_10065c60(local_84);
        goto LAB_10065e62;
      }
LAB_10065e58:
      FUN_10064520(DAT_1021a0e4,"I don\'t know that command.");
    }
    else {
      (*pcVar3)(pcVar5 + 1);
    }
  }
LAB_10065e62:
  *szInputBuffer = '\0';
  FUN_10080f60(&DAT_100d39c5,0);
LAB_10065e74:
                    /* 0x14e0 = CInput->iInputEnabled */
  if (*(int *)(iParm1 + 0x14e0) != 0) {
    if (DAT_1021a0e4 != 0) {
      CChat->ScrollToBottom_100637c0();
    }
    CInput->Close_100658e0();
  }
  return;
}
	 
 
I found out that nop'ing samp+0x80f60 function results in the chat input box not being cleared (despite processing the command/text itself), so I assume it has something to do with it. I noticed the same behaviour when noping the first function that is called within 0x80f60:
	
	
	
		Code:
	
	
		        10080f6b 50              PUSH       EAX
        10080f6c 8b cf           MOV        ECX,EDI
        10080f6e e8 bd 69        CALL       FUN_10097930                                 
                 01 00
	 
 
But I didn't have much luck trying to call 0x80f60 "remotely"...
Edit: It certainly looks like some kind of "cleanup" function for the input box:
	
	
	
		C++:
	
	
		void __thiscall FUN_10080f60(int iParm1,undefined4 param_1)
{
  undefined4 uVar1;
 
  FUN_10097930(param_1);
                    /* 0x122 = CInput->szInputBox->horizontalScrollOffset (a.k.a. how many
                       characters are hidden on the left side) */
  *(undefined4 *)(iParm1 + 0x122) = 0;
  uVar1 = (*(code *)0xeacf4)(*(undefined4 *)(iParm1 + 0x4d));
  FUN_10080e50(uVar1);
  if ((char)param_1 != '\0') {
                    /* Set cursor pos to the begining */
    *(undefined4 *)(iParm1 + 0x11e) = 0;
    return;
  }
                    /* 0x119 = CInput->stInputBox->markedTextEndOffset */
                    /* 0x11e = CInput->szInputBox->textCursorPos */
  *(undefined4 *)(iParm1 + 0x11e) = *(undefined4 *)(iParm1 + 0x119);
  return;
}